What’s Your Impression? 2 Full Pages

F a cia l r e co gn i on w it h f a m ilia r p eo ple i s e asy , b ut t r y in g t o r e co gn iz e s o m eo ne b ase d o nly o n d esc rip on i s c h alle n gin g.

E rik S .

L e sse r/ A sso cia te d P re ss B ulle t s tr ia ons a re d is nct i m pre ssio ns t h at c a n b e u se d t o m atc h b ulle ts t o t h e g u n t h ey w ere ﬁ re d f r o m . W hat a re s o m e o th er e xa m ple s o f s tr ia ons? A le xa ndre M en eg hin i/ A sso cia te d P re ss C hap te r 7 P atte rn E vid en ce I : G en era l P atte rn s a n d F in gerp rin ts A ndy C arp en ea n/L a ra m ie B oom era ng/A sso cia te d P re ss L e arn in g O bje c ve s A er r e ad in g t h is c h ap te r, y o u s h o uld b e a b le t o d o t h e f o llo w in g: D esc rib e p a ern e vid en ce t h at c a n b e u se d f o r i d en ﬁca on, i n div id ualiz a on, a n d r e co nstr u c on. E xp la in t h e c o lle c on a n d p re se rv a on o f p a ern e vid en ce . E xp la in h ow p a ern e vid en ce i s a n aly ze d . S u m mariz e t h e n atu re a n d h is to ry o f ﬁ nge rp rin ts a n d t h eir r o le i n p ers o nal i d en ﬁca on. D is c u ss h ow ﬁ nge rp rin t e vid en ce i s c o lle cte d a n d p re se rv e d . E xp la in h ow ﬁ nge rp rin ts a re a n aly ze d . C h. 7 I n tro duc on I n t h is a n d f o llo w in g c h ap te rs , w e w ill d is c u ss p a ern e vid en ce . M an y o f t h e t o pic s c o nce rn p a ern s f o r i n div id ualiz a on, i n clu din g p hysic a l p a ern s, ﬁ nge rp rin ts , f o otp rin ts , f o otw ear a n d re i m pre ssio ns, h an dw ri ng, ﬁ re arm s a n d t o ol m ark i d en ﬁca on, b it e m ark s, a n d b lo odsta in p a ern s. T h is c h ap te r l o oks c lo se ly a t p hysic a l p a ern s ( b ro ke n o r t o rn o bje cts ) a n d ﬁ nge rp rin ts ( a m ajo r c a te go ry o f i n div id ualiz a on p a ern ). P a ern e vid en ce c a n b e v e ry i m po rta n t i n a n i n ve s ga on, b eca u se i t i n clu des m an y t y p es o f e vid en ce f a m ilia r t o m ost p eo ple . S o m e t y p es o f p a ern s c a n p o te n ally b e i n div id ualiz e d — th at i s , a rib ute d t o a s p eciﬁ c s o urc e . I n t h is w ay, p eo ple c a n b e a sso cia te d w it h o r d is so cia te d f r o m s p eciﬁ c p la ce s, l ik e s c e n es, o r f r o m o th er p eo ple . C onclu sio ns f r o m p a ern e vid en ce c o m paris o ns a re u su ally m ore d eﬁ ni ve t h an t h o se f r o m t ra ce o r c h em ic a l e vid en ce , a n d c o rre sp o ndin gly m ore u se fu l t o j u rie s a n d j u dge s. P a ern e vid en ce i s e xa m in ed b y t h e e ye , f o r t h e m ost p art. N o c o m plic a te d i n str u m en ts , o th er t h an t h e o cca sio nal u se o f m ic ro sc o pes, a re r e q uir e d . S o m e m es, a p a ern e vid en ce m atc h c a n b e o bvio us t o a n yo ne, s u ch a s i n a p hysic a l p a ern m atc h ( jig sa w ﬁ t), m akin g t h e e vid en ce e asie r t o p re se n t t o a c o urt. 7 .1 C la ssiﬁ ca on o f P a ern E vid en ce P a ern e vid en ce c a n b e c la ssiﬁ ed i n to t h re e o ve ra rc h in g c a te go rie s: p a ern s f o r i d en ﬁca on , p a ern s f o r i n div id ualiz a on , a n d p a ern s f o r r e co n str u c on .

T h is i d ea f o llo w s b y a n alo gy f r o m t h e t h re e a c vi es t h at c a n c o m pris e t h e e le m en ts o f a f o re n sic i n ve s ga on— id en ﬁca on, i n div id ualiz a on, a n d r e co nstr u c on— th at w e d is c u sse d i n C hap te r 1 . S o , j u st a s w e c a n t a lk a b o ut i d en ﬁca on, i n div id ualiz a on, a n d r e co nstr u c on a s e le m en ts o f a c rim in alis cs i n ve s ga on, s o i n t h e s a m e w ay w e c a n t a lk a b o ut p a ern e vid en ce c a te go rie s t h at h ave t h ese e le m en ts a s t h eir g o als . I d en ﬁca on ( o r c la ssiﬁ ca on) p a ern s, w hic h a re u se d t o i d en fy t h in gs i n o ur e ve ry d ay e n vir o nm en t b y g e n era l s h ap e a n d f o rm , a re a p plie d i n f o re n sic w ork t o h air c o m paris o ns ( C hap te r 5 ) a n d h an dw ri ng ( C hap te r 8 ). T h e d iﬀ ere n t i n div id ualiz a on p a ern s t h at a re i m po rta n t i n f o re n sic w ork a re d is c u sse d i n d eta il i n t h is a n d t h e n ext c h ap te r. I n l a te r c h ap te rs , w e b rie ﬂ y d is c u ss s o m e r e co nstr u c on p a ern s, i n clu din g b lo odsta in p a ern s. B efo re s p eciﬁ c t y p es o f p hysic a l p a ern s a re d is c u sse d , l e t’s g o o ve r e ach c a te go ry o f p a ern e vid en ce . P a ern s f o r I d en ﬁca on P a ern s f o r i d en ﬁca on a re u se d t o i d en fy o bje cts a n d p eo ple i n o ur e ve ry d ay l if e a n d e xp erie n ce . F o r i n sta n ce , r ig h t n ow , y o u m ig h t b e s i ng a t a t a b le . H ow d o y o u k n ow i t ’s a t a b le ? Y o u m ig h t s a y: " I k n ow i t ’s a t a b le j u st b y l o okin g a t i t ." T h e r e aso nin g b eh in d y o ur k n ow le d ge i s t h at y o ur b ra in h as a r e co rd o f t h e p a ern o f a t a b le , w hic h y o u l e arn ed w hen y o u w ere y o unge r. T h is p a ern h as t o d o w it h t h e s h ap e a n d f o rm o f a t a b le : i t s f o ur l e gs a n d ﬂ at t o p. T h ere a re v a ria ons o f t a b le s i n t h e w orld , b ut o n t h e b asis o f t h eir g e n era l p a ern , w e c la ssif y t h em a ll a s " ta b le s." W hen y o u s e e t h is p ar cu la r p a ern , i t m atc h es u p w it h t h e b ra in p a ern t h at i d en ﬁes i t a s a " ta b le ." T h is w ork s t h e s a m e w ay f o r f a cia l r e co gn i on. Y o u r e co gn iz e p eo ple y o u k n ow i n sta n tly — eve n i n a l a rg e c ro w d a n d e ve n i f y o u h ave n ’t s e en t h em i n a l o ng m e. B ut w hat i f o ne o f y o ur f r ie n ds t r ie s t o d esc rib e s o m eo ne n ew t o y o u i n e n o ugh d eta il f o r y o u t o ﬁ nd t h is s tra n ge r i n a c ro w ded p la ce , l ik e a n a ir p o rt? N o m a er h ow m uch d eta il i s p ro vid ed , y o u m ay n o t ﬁ nd h im o r h er. I t i s v e ry d iﬃ cu lt t o e n um era te t h e f e atu re s a n d p ro per es o f a p ers o n’s f a cia l p a ern t h at o ne p ers o n r e co gn iz e s i n e n o ugh d eta il t o a llo w s o m eo ne e ls e t o d o s o . T h e h um an m in d i s v e ry g o od a t p a ern r e co gn i on, b ut i t i s n o t y e t c le ar i n a d eta ile d w ay h ow i t w ork s. I n f o re n sic w ork , t h e e xa m in a ons t h at m ost c lo se ly r e se m ble t h is t y p e o f p a ern a re h air c o m paris o ns a n d h an dw ri ng c o m paris o ns. I n c o m parin g h air s o r h an dw ri ng s a m ple s, t h e e xa m in er l o oks a t s p eciﬁ c f e atu re s i n t h e k n ow n a n d t h e q ues oned s a m ple . B ut t h e c o m paris o n i s m ore t h an j u st a c h eck lis t o f w hic h f e atu re s m atc h . T h e e xa m in er i n co rp o ra te s t h e s u m o f a ll t h ese f e atu re c o m paris o ns i n to a n o ve ra ll p a ern c o m paris o n b etw een t h e q ues oned a n d k n ow n. I t i s a l o t l ik e t h e f a cia l r e co gn i on e xa m ple . R eco gn iz in g s o m eo ne’s f a ce i s m ore i n vo lv e d t h an a s im ple c h eck lis t o f t h e f e atu re s t h at a re c o m pare d . O ne o f t h e i m po rta n t t h in gs t h at d is ngu is h h an dw ri ng a n d h air c o m paris o ns f r o m t h e o th er e vid en ce c a te go ry c o m paris o ns i s i n tra ‐in div id ual v a ria b ilit y , w hic h m ean s t h at t h ere i s v a ria b ilit y i n t h e k n ow ns t h em se lv e s, a n d t h is m ust b e t a ke n i n to c o nsid era on i n t h e c o m paris o n. P a ern s f o r I n div id ualiz a on P a ern s f o r i n div id ualiz a on a re c h ara cte ris c o f e vid en ce t h at c a n b e u niq ue a m ong t h e m em bers o f t h eir c la ss. T h is c a n b e v e ry i m po rta n t a sso cia ve e vid en ce i n a n i n ve s ga on. W e m ig h t b e a b le t o ﬁ gu re o ut t h at a p ar cu la r re m ad e a re m ark , o r a p ar cu la r p ie ce o f f o otw ear m ad e a n i m pre ssio n, o r t h at b ro ke n p ie ce s o f a h ead lig h t l e n s c a m e f r o m a s p eciﬁ c c a r i n a h it a n d r u n, w hic h m ay e a s u sp ect t o t h e s c e n e o f a c rim e. T h ere a re t w o m ajo r t y p es o f i n div id ualiz a on p a ern s: p hysic a l m atc h p a ern s a n d i m pre ssio ns. P hysic a l M atc h es P hysic a l m atc h p a ern s a re f o rm ed f r o m t h e p ie ce s o f r a n do m ly b ro ke n o bje cts a n d a re s o m e m es c a lle d j ig sa w ﬁ t m atc h es. T h e p a ern s a re l ik e a p ic tu re p uzzle . F o r i n sta n ce , i f a g la ss w as b ro ke n a n d t h ere w ere n ’t t o o m an y p ie ce s, i t w ould n’t t a ke l o ng t o ﬁ gu re o ut h ow t h e p ie ce s ﬁ t b ack t o ge th er t o f o rm t h e o rig in al g la ss. E ve n i f s o m e p ie ce s w ere m is sin g, i t w ould b e l ik e ly t h at a t l e ast a f e w p ie ce s w ould ﬁ t t o ge th er. N ote t h at t h is w ork s f o r s o lid o bje cts t h at f r a ctu re i n a r a n do m f a sh io n. I n c a se s o f s o lid o bje cts , t h ese p hysic a l m atc h es a re a ls o k n ow n a s f r a ctu re m atc h es . S u ppo se t h at s e ve ra l p ie ce s o f a b ro ke n g la ss w ere f o und a t a c rim e s c e n e. L a te r, a s u sp ect w as d eve lo ped a n d p o lic e s e arc h ed h is a p artm en t. I n t h e c u ﬀ o f a p air o f p an ts , a p ie ce o f g la ss w as f o und. T h e l a b p erfo rm ed a n a n aly sis a n d p hysic a lly m atc h ed t h e p an ts ‐c u ﬀ p ie ce t o t h e g la ss p ie ce s f r o m t h e s c e n e. T h is e vid en ce g o es a l o ng w ay t o w ard p u ng t h e o w ner o f t h ese p an ts a t t h e s c e n e a ro und t h e m e t h e g la ss w as b ro ke n . T h in k A bo ut I t I n t h e p re vio us e xa m ple a b o ut t h e s u sp ect a n d t h e p ie ce o f b ro ke n g la ss, a re y o u c o nvin ce d t h at t h is e vid en ce p la ce s t h e s u sp ect a t t h e s c e n e a ro und t h e m e t h e g la ss w as b ro ke n ? W hat i f y o u w ere a n e xp ert w it n ess a n d t h e s u sp ect’s l a w ye r a sk e d , " H ow d o y o u k n ow g la sse s b re ak r a n do m ly ? W hy c o uld n’t t h ere h ave b een a n o th er g la ss i n m y c lie n t’s k it c h en t h at b ro ke i n a w ay t h at p ro duce d t h e p ie ce t h e p o lic e f o und, a n d i t j u st h ap pen ed t o ﬁ t t h e s c e n e p ie ce s? " H ow w ould y o u a n sw er t h e l a w ye r’s q ues on? H ow w ould y o u p ro ve t h at g la ss b re aks r a n do m ly a n d s h ow t h at t h is i s r e ally a n i n div id ualiz a on? W hen t h e o bje ct t h at f r a ctu re s i s s o lid a n d b re aks i n a r a n do m f a sh io n, t h e p hysic a l m atc h in g o f t h e p ie ce s i s c a lle d d ir e ct , o r s o m e m es p rim ary .

I f a n o bje ct o r i t e m i s n ’t s o lid o r f r a ctu re s i n a w ay t h at d o esn ’t r e su lt i n c le an , s m ooth f r a ctu re s u rfa ce s— su ch a s p ie ce s o f c u t o r t o rn f a b ric o r a s n ap ped p ie ce o f w ood w it h r a g ge d i r re gu la r e n ds— th e p hysic a l m atc h i s c a lle d i n dir e ct , o r s e co n dary .

E xp erts c a n w ork t o t r y t o ﬁ t t h ese p ie ce s b ack t o ge th er, b ut e ve n i f t h e m atc h l o oks r ig h t, t h ere i s u nce rta in ty . I t i s m uch e asie r t o i m agin e a p ie ce o f s im ila r c u t o r t o rn f a b ric " m atc h in g" a n u nkn ow n b y c h an ce t h an i t i s i n t h e b ro ke n g la ss c a se . E xp erts w ill n o t g e n era lly s a y t h at s e co ndary p hysic a l m atc h es a re t r u e i n div id ualiz a ons. I n ste ad , t h ey m ig h t s a y t h e p ie ce s ﬁ t, a n d a re c o nsis te n t w it h h avin g b een p art o f t h e s a m e o rig in al, b ut t h ey c a n no t c o nﬁ rm a c o m mon o rig in . I m pre ssio ns A no th er m ajo r t y p e o f i n div id ualiz a on p a ern i s i m pre ssio ns .

I m pre ssio ns o ccu r w hen t w o o bje cts c o m e i n c o nta ct w it h o ne a n o th er, a n d o ne o bje ct l e ave s b eh in d d is ngu is h in g m ark in gs o n o r i n t h e o th er. T h ere a re t h re e t y p es o f i m pre ssio ns, w hic h a re d is ngu is h ed b ase d o n d ep th a n d h ow t h e m ark s a re m ad e. I m pre ssio ns t h at a re e sse n ally s ta m ped b y a n o bje ct i n to o r o nto a n o th er a re c a lle d i m prin ts i f t h ey a re m ore o r l e ss ﬂ at ( t w o‐d im en sio nal) . T h ey a re c a lle d i n den ta ons i f t h ey h ave d ep th ( t h re e‐d im en sio nal c h ara cte r). F o r e xa m ple , m an y ﬁ nge rp rin ts a n d re i m pre ssio ns a re i m prin ts b eca u se t h ey a re l e o n h ard s u rfa ce s. H ow eve r, t h ey c a n b e i n den ta ons i f t h ey a re l e i n a s o r e ce iv in g m ed iu m , s u ch a s a ﬁ nge rp rin t i n s o t a r, o r a re i m pre ssio n i n s o s o il. I f t h e r e ce iv in g s u rfa ce i s m ark e d b y a n o bje ct o r s u rfa ce m ovin g a cro ss i t — in e ﬀ ect, b ein g s c ra tc h ed b y i t — th e m ark s a re c a lle d s tr ia ons .

T h e m ark in gs o n b ulle ts t h at ﬁ re arm s e xa m in ers u se t o i d en fy t h e g u n f r o m w hic h a b ulle t c a m e a re s tr ia ons. A ny s lid in g t o olm ark , l ik e a m ark m ad e b y a s c re w driv e r s c ra p in g a cro ss a l a tc h p la te o n a d o or, i s a ls o a s tr ia on. P a ern s f o r R eco nstr u c on P a ern s f o r r e co nstr u c on h elp c re ate t h eo rie s o f t h e e ve n ts t h at o ccu rre d a t a s c e n e. R eco nstr u c on p a ern s i n clu de g la ss f r a ctu re s, f u rn it u re a n d o bje cts a t a s c e n e, t ra ck s, t ra ils , t ra je cto rie s o f p ro je c le s, s k id m ark s i n a u to a ccid en ts , a n d m ore . F ra ctu re p a ern s i n g la ss c a n h elp d ete rm in e w hat c a u se d t h e b re aka ge . T h e d is tr ib u on a n d c o ndi on o f c lo th in g a n d o bje cts a t s c e n es c a n h elp t o d ete rm in e w hat h ap pen ed , i f t h ere w as a s tr u ggle , m ove m en ts o f p ers o ns i n vo lv e d , a n d s o f o rth . T ra ck s a n d t ra ils c a n h elp s h ow t h e d ir e c on o f m ove m en t o f p eo ple . P ro je c le t ra je cto rie s, s u ch a s t h e p ath f o llo w ed b y a b ulle t i n a s h o o ng c a se , c a n h elp r e co nstr u ct t h e p o si on o f t h e w eap o n w it h r e sp ect t o t h e t a rg e t. S kid m ark s h elp a u to m obile a ccid en t r e co nstr u c onis ts d ete rm in e t h e d ir e c on a n d s p eed o f v e h ic le s j u st p rio r t o a n a ccid en t. D ep en din g o n t h e s p eed a n d d ir e c on o f a v e h ic le a t t h e m e i t s b ra ke s a re a p plie d , a re s k id m ark w it h a p ar cu la r l e n gth a n d d ir e c on i s c re ate d . D ocu m en ta on a n d m easu re m en ts o f t h e m ark s c a n h elp r e co nstr u ct d ir e c on a n d s p eed . T h ere a re c o m pute r p ro gra m s n ow t h at a ssis t t ra ﬃ c a ccid en t r e co nstr u c on s p ecia lis ts i n t h ese t a sk s. S n ow p rin ts a re a m ong t h e m ost d iﬃ cu lt i n den ta on m ark in gs t o c o lle ct a n d p re se rv e . C an y o u t h in k o f a n y o th er e n vir o nm en ts w here p a ern e vid en ce w ould b e e xtra h ard t o r e co gn iz e , c o lle ct, a n d p re se rv e ? J o h ner/ S u perS to ck A naly sis o f p a ern e vid en ce , s u ch a s t h is s n eake r s o le , r e q uir e s t h at t h e c o rre ct t y p e o f i m pre ssio n ( p o si ve o r n ega ve ) a n d o rie n ta on i s u se d t o m ake a c o m paris o n b etw een t h e u nkn ow n a n d t h e k n ow n m ark . B it e m ark e vid en ce i s n o t a s a cce p te d f o r i n div id ualiz a on t o day a s i t w as d urin g T e d B undy’s t r ia l. A sso cia te d P re ss 7 .2 C olle c on a n d P re se rv a on o f P a ern E vid en ce T h ere a re d iﬀ ere n t w ays o f c o lle c ng p a ern e vid en ce , d ep en din g o n t h e m ark in gs o r i m pre ssio ns l e b eh in d. T w o i m po rta n t t e rm s t o k n ow a re p osi ve a nd n eg a ve i m pre ssio n s .

A p o si ve i m pre ssio n i s i d en ca l t o t h e o bje ct t h at m ad e i t , w here as a n ega ve i m pre ssio n i s i t s m ir ro r i m age . T h e s h o e p rin ts l e i n t h e m ud a re n ega ve i m pre ssio ns; t h ey a re n ega ve s o f t h e s h o es’ s o le s. I n t h is s c e n ario , t h e p o si ve s w ould b e t h e s h o es’ s o le s. T h e s a m e i s t r u e i n t h e c a se o f a re i n den ta on. T h is m ark w ould b e c o lle cte d b y c a s ng. T h e r e su l ng c a st i s a p o si ve , l ik e t h e re t h at m ad e t h e m ark , s o t h e c a st c a n b e c o m pare d t o t h e re . I n g e n era l, i m prin t m ark in gs a re c o lle cte d b y ﬁ rs t p ho to gra p hin g t h e m ark w it h a n d w it h o ut a s c a le p re se n t, a n d t h en e it h er c o lle c ng t h e w ho le o bje ct t h at h as t h e m ark , o r i f t h at i s n o t p o ssib le , b y t a p e l i in g. I f t h e i m prin t m ark in gs a re m ad e u p o f d ir t o r g re ase o r o th er r e sid ues, t h ey c a n b e l i ed f r o m a s u rfa ce w it h s ck y t a p e ( s im ila r t o S co tc h ® t a p e). T h e t a p e m ust b e p la ce d o nto t h e s u rfa ce w it h c a re , t o a vo id c re a ng a n y b ubble s. A r u bber r o lle r c a n h elp i n t h is p ro ce ss. T h en t h e t a p e i s c a re fu lly l i ed , s o a s t o a vo id a n y d am age t o o r d is to r on o f t h e m ark , a n d p la ce d o nto a c o ntra s ng b ack in g s u rfa ce . A b la ck m ark , f o r e xa m ple , w ould b e p la ce d o nto a w hit e b ack in g s u rfa ce . T h is i t e m i s t h en l a b ele d w it h t h e u su al r e q uir e d i n fo rm a on a n d p la ce d i n to a p ap er o r p la s c c o nta in er a n d s e ale d . L i in g t a p es o f v a rio us s iz e s a n d a p pro pria te b ack in gs a re c o m merc ia lly a va ila b le . I n den ta on m ark in gs m ust a ls o b e p ho to gra p hed . A s m en oned e arlie r, s id e l ig h ng h elp s g iv e t h e i m pre ssio n b e er c o ntra st. A er p ho to gra p hy, t h e m ark i s c a st. F o r t h is p urp o se , d en ta l s to ne i s u se d . T h is i s a s p ecia l ﬁ nely g ro und p la ste r u se d b y d en sts t o m ake m old s f o r r e sto ra ons. I t i s m ix e d w it h w ate r t o m ake a p an ca ke ‐ b a er c o nsis te n cy m ix tu re , t h en p o ure d i n to t h e i n den ta on s o a s n o t t o d is tu rb a n y o f t h e d eta il p re se n t. O nce i t h ard en s, i t c a n b e r e m ove d . I t c a p tu re s ﬁ ne d eta il q uit e w ell. I n a d di on t o l a b elin g t h e p ack a gin g o f a c a st, t h e c o lle cto r c a n s c ra tc h a c a se n um ber o r i t e m n um ber i n to t h e t o p s id e o f t h e h ard en in g d en ta l s to ne. T h ere a re s p ecia l t y p es o f c a s ng m ate ria ls f o r t o ol m ark s, f o r m ark s i n s n ow , a n d o th er s p eciﬁ c t y p es o f m ark s. T o ol m ark s a re d is c u sse d i n a l a te r c h ap te r, b ut f o r n ow , d en ta l s to ne i s n o t c a p ab le o f c a p tu rin g t h e v e ry ﬁ ne d eta il i n a t o ol m ark ( lik e a s tr ia on m ark m ad e b y a s c re w d riv e r o n a l o ck p la te ). T h ere a re s ilic o ne‐b ase d m ate ria ls c o m merc ia lly a va ila b le t h at a re b e er s u it e d f o r t h is t a sk . T h ese s ilic o ne‐b ase d m ate ria ls c a n a ls o b e u se d f o r i n den ta on‐t y p e ﬁ nge rp rin ts , s u ch a s a ﬁ nge rp rin t i n w ax. I n den ta on m ark in gs i n s n ow p o se a p ro ble m b eca u se d en ta l s to ne g iv e s o ﬀ h eat a s i t h ard en s, a n d t h e h eat c a n m elt t h e s n ow a n d d estro y t h e i m pre ssio n d eta il. P ro ducts l ik e S n ow P rin t W ax c a n b e s p ra ye d o nto t h e m ark t o p ro te ct i t f r o m t h is e ﬀ ect. A n i n den ta on i m pre ssio n i s a n ega ve , a n d s o t h e c a st o f t h e i m pre ssio n i s a p o si ve . A cco rd in gly , t h e c a st c a n b e c o m pare d d ir e ctly w it h t h e re o r f o otw ear o r o th er i t e m t h at i s t h o ugh t t o h ave m ad e t h e i n den ta on. B oth i n c o lle c ng e vid en ce a n d i n t h in kin g a b o ut h ow p a ern c o m paris o ns a re d o ne, i t i s i m po rta n t t o r e m em ber t h at c o m paris o ns m ust b e m ad e b etw een l ik e i m pre ssio ns. L e w it h l e , r ig h t w it h r ig h t, p o si ve w it h p o si ve , a n d n ega ve w it h n ega ve . T h e d eta ile d i n div id ual c h ara cte ris cs t h at h elp i n i n div id ualiz in g t h e m ark m ust b e i n t h e s a m e o rie n ta on a s t h e o rig in al o bje ct t h at m ad e t h e m ark ( o r a s i t s m ir ro r i m age ). S o m e m es, t h is r e q uir e s t h at t h e l a b c re ate a k n ow n f r o m t h e s u sp ecte d i t e m i n o rd er t o m ake t h e c o m paris o n. F o r e xa m ple , a l i ed f o otw ear i m pre ssio n f r o m a s c e n e w ould b e c o m pare d w it h a n i n ke d i m pre ssio n o f t h e s u sp ecte d f o otw ear m ad e i n t h e l a b o ra to ry . T h in k A bo ut I t I m agin e y o u a re a p a ern e vid en ce e xa m in er, a n d t h e p o lic e b rin g y o u a t a p e‐li ed i m pre ssio n o f a re t h ey h ave g o en f r o m a ﬂ at c o ncre te s u rfa ce . T h ey h ave a s u sp ect c a r, b ut i t i s u p t o y o u t o ﬁ gu re o ut h ow t o c o m pare t h e re s w it h t h e i m pre ssio ns. H ow w ould y o u m ake t h e k n ow n s p ecim en s f r o m t h e re s t o u se f o r c o m paris o n w it h t h e q ues oned i m pre ssio n? 7 .3 A naly sis o f P a ern E vid en ce I n C h ap te r 1 .4 ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ se c1 .4 #se c1 .4 ) , c la ss a n d i n div id ual c h ara cte ris cs w ere i n tro duce d . T h ese c o nce p ts b eco m e v e ry i m po rta n t i n p hysic a l p a ern a n aly sis . C onsid er i t e m s l ik e s h o es o r re s. T h ere a re h undre d s, o r m ayb e e ve n t h o usa n ds, o f i d en ca l s h o es a n d re s i n t h e w orld . T h ey w ere m an ufa ctu re d u nder q ualit y c o ntro l s ta n dard s t o b e a s s im ila r a s p o ssib le . S o , i f a b ra n d n ew s h o e o r re l e ave s a n i m pre ssio n, w hat c h ara cte ris cs m ake u p t h at i m pre ssio n? C la ss c h ara cte ris cs. W it h a n ew s h o e, t h e s o le p a ern , m an ufa ctu re r, s iz e , t y p e o f s h o e, e tc ., c a n b e d ete rm in ed . H ow eve r, i t i s i m po ssib le t o d is ngu is h a n y i n div id ual s h o e i n t h at c la ss, b eca u se t h ere a re n o t y e t a n y i n div id ual c h ara cte ris cs. T h e s a m e r u le a p plie s t o re s. I n div id ual c h ara cte ris cs c o m e a b o ut a s a r e su lt o f w ear. S o le o r re p a ern f e atu re s w ear d ow n i n n o n‐u nif o rm w ays, p arts o f t h e s o le o r re c a n b e c u t o r t o rn b y w ear, f o re ig n o bje cts c a n m ake u nusu al m ark s i n t h e s o le o r re m ate ria l, a n d s o o n.

T h e f o re n sic e xa m in er w ill m ake a c o m paris o n b etw een a q ues oned m ark a n d a k n ow n o bje ct. I f y o u r e ca ll, q ues oned o bje cts a re f o und a t t h e s c e n e a n d h ave a n u nkn ow n s o urc e . K n ow n o bje cts h ave a k n ow n s o urc e a n d c a n h elp t o d ete rm in e t h e s o urc e o f a q ues oned o bje ct. H ere , t h e m a er o f q ues oned a n d k n ow n s p ecim en s b eco m es a l i le m ore c o m plic a te d w it h t h e i n clu sio n o f p o si ve o r n ega ve i m pre ssio ns. A s n eake r s o le i t s e lf , f o r i n sta n ce , c a n no t b e c o m pare d w it h t h e i m pre ssio n m ark b eca u se p o si ve s a n d n ega ve s c a n no t b e c o m pare d d ir e ctly . T h e f e atu re s o f i n te re st w ould b e m ir ro r‐im age d . T a ke a g o od l o ok a t F ig u re 7 .1 . F ig u re 7 .1 : S n eake r s o le i m pre ssio ns T h e ﬁ gu re s h ow s a r ig h t s n eake r, b ut i t i s a m ir ro r i m age w it h r e sp ect t o t h e i n ke d i m pre ssio n o n t h e b ro w n p ap er. T o m ake a c o m paris o n, t h e s n eake r m ust b e u se d t o m ake a k n ow n n ega ve i m pre ssio n. T h is m ig h t b e a n i n ke d i m pre ssio n o n p ap er, o r o n t ra n sp are n t p la s c. T h ese a re g o od s u rfa ce s f o r c a p tu rin g t h e d eta il i n t h e f o otw ear i n a p pro xim ate ly t h e s a m e w ay a s i t w as c a p tu re d i n t h e e vid en ce m ark . N ote t h at t h ese i n ke d i m pre ssio ns w ould b e m ad e b y s o m eo ne a ctu ally w earin g t h e s n eake r a n d t a kin g a s te p , s o t h at t h ere w ould b e w eig h t o n t h e s h o e. T h e m id dle i m pre ssio n o n t ra n sp are n t p la s c i n F ig u re 7 .1 i s t u rn ed t o m atc h t h e o rie n ta on o f t h e s n eake r i n t h e p ic tu re , b ut i f i t i s t u rn ed o ve r, i t w ill m atc h t h e o rie n ta on o f t h e p ap er p rin t. A s a n i n ke d s n eake r i m pre ssio n, i t i s a n ega ve , a n d t h ere fo re c o uld b e u se d a s t h e k n ow n f o r a n u nkn ow n i m prin t t h o ugh t t o h ave b een m ad e b y t h at s n eake r. Y o u c a n a ls o s e e f r o m F ig u re 7 .1 h ow i t w ould b e e asy t o c o nfu se l e a n d r ig h t i f y o u d o n’t k e ep t ra ck o f w hat y o u a re d o in g w hen m akin g t h ese i m pre ssio ns o n t ra n sp are n t s u rfa ce s. P hysic a l M atc h es T h ere a re f o ur c rit e ria t h at m ust b e m et i n o rd er t o s ta te t h at e vid en ce i s i n div id ualiz e d i n a f r a ctu re m atc h . T h e c rit e ria i n clu de: 1 . T h e o bje cts m ust b e b ro ke n o r t o rn o r c u t. 2 . T h ey m ust b e c a p ab le o f b ein g r e alig n ed . 3 . T h ere m ust b e a j ig sa w ﬁ t ( o r l o ck a n d k e y ﬁ t) s u rfa ce t o s u rfa ce . 4 . T h e m atc h m ust b e u niq ue. W it h i n dir e ct o r s e co ndary m atc h es, s u ch a s t o rn f a b ric s, i t i s u nlik e ly t h at i n div id ualit y c a n b e d ecla re d , e ve n i f t h e p ie ce s a p pear t o ﬁ t. I t i s n ’t i n tu i ve t h at e ve ry f a b ric c u t o r t e ar w ill b e c o m ple te ly r a n do m a n d t h us u niq ue. T h is m ean s t h at t h ere i s a p o ssib ilit y o f a c h an ce d uplic a te . T w o d iﬀ ere n t c u ts , o r e ve n t e ars , o f a f a b ric c o uld b e s o s im ila r a s t o b e i n dis ngu is h ab le i n a c o m paris o n. P hysic a l m atc h in g i s d o ne b y t h e e ye , o r w it h t h e a id o f a m agn iﬁ er o r s te re o m ic ro sc o pe. T h is i s a m ic ro sc o pe w it h t w o e ye p ie ce s ( e n ab lin g s te re o v is io n) t h at i s e sse n ally a m agn iﬁ er. T h is t y p e o f m atc h in g i s i n tu i ve a n d q uit e f a m ilia r t o p eo ple . A s a r e su lt , i t i s v e ry c o nvin cin g f o r a j u ry o r j u dge , b eca u se t h ey c a n l o ok a t i t a n d s e e i t f o r t h em se lv e s. I m pre ssio ns W it h t h e o th er i m pre ssio ns t h at h ave b een d is c u sse d , s u ch a s t h o se f r o m s h o es o r re s, t h e c o m paris o n i s m ore s u bje c ve a n d w ill d ep en d o n t h e e xa m in er’s t ra in in g a n d e xp erie n ce . T h ese c o m paris o ns a re a ls o d o ne b y t h e e ye o r w it h t h e a id o f s im ple m agn iﬁ ers . T h e i n div id ual c h ara cte ris cs m ust b e l o ca te d a n d t h eir p o si on w it h in t h e o ve ra ll p a ern n o te d . W it h e xp erie n ce , e xa m in ers d eve lo p a s e n se o f w hat t h e d iﬀ ere n t i n div id ual c h ara cte ris cs a re i n e ach i m pre ssio n. T h ey a ls o l e arn t o j u dge t h e q ualit y o f t h e i m pre ssio n a n d h ow m an y i n div id ual c h ara cte ris cs i t p o sse sse s. A s y o u c a n i m agin e, n o t e ve ry i m pre ssio n g iv e s g o od d eta il. I t m ig h t b e l ig h t, o r s m udge d , o r d is to rte d . E xa m in ers u se t h ese f a cto rs t o d ete rm in e i f k n ow n a n d u nkn ow n m ark in gs m atc h . T h ere i s n o r u le a b o ut h ow m an y m atc h in g i n div id ual c h ara cte ris cs m ust b e p re se n t t o d ecla re t h at t h e k n ow n i s t h e s o urc e o f t h e q ues oned . T h is d ete rm in a on i s u p t o t h e e xa m in er a n d i s t h us m ore s u bje c ve . U nlik e a p hysic a l m atc h , t h ese c o m paris o ns a re n o t i n tu i ve o r o bvio us, a n d t h e s k ill t o d o t h em c o m es o nly f r o m e xte n siv e t ra in in g a n d e xp erie n ce . A s w it h t h e r a n do m f r a ctu rin g o f s o lid o bje cts , i n div id ualit y d ue t o w ear c o m es a b o ut b eca u se t h e a ccid en ta ls , t h e i n div id ual c h ara cte ris cs a cq uir e d b y t h e i t e m , a re e xp ecte d t o b e r a n do m . W it h a s n eake r s o le , f o r e xa m ple , t h is m ig h t b e a c u t o r a p ar cu la rly w orn a re a. A n e xa m in er m ust u se h is o r h er t ra in in g a n d j u dgm en t t o a sse ss t h e q ualit y o f t h e i m pre ssio n, a n d t h e n um ber a n d d is tr ib u on o f i n div id ual c h ara cte ris cs t h at w ere t ra n sfe rre d t o t h e m ark f r o m t h e o bje ct. T h ese f a cto rs h elp t h e e xa m in er t o d ecid e w hat c o nclu sio n t o d ra w f r o m t h e c o m paris o n. O th er p a ern s c a n f a ll i n to t h is g e n era l c a te go ry . O cca sio nally , a l ip p rin t o r e ar p rin t i s e xa m in ed . T h ese i m prin ts a re u nusu al, s o t h ere i s n o t m uch e xa m in er e xp erie n ce w it h o r r e se arc h o n t h em . T h us, t h ere i s n o t m uch o f a b asis f o r ﬁ ndin g e n o ugh i n div id ual c h ara cte ris cs t o r e ach a n u nam big u o us c o nclu sio n. S o ck p rin ts o r g lo ve p rin ts m ay b e i n clu ded h ere , a s w ell a s f a b ric i m pre ssio ns, s u ch a s w hen a b lo od‐ s o ake d f a b ric i s p re sse d a ga in st a n o nab so rb en t s u rfa ce a n d l e ave s a n i m pre ssio n i n b lo od. S o m e m es, i n a h it ‐ a n d‐r u n c a se , t h e p a ern o f t h e f a b ric f r o m t h e c lo th in g o f a v ic m c a n b e i m pre sse d i n to t h e b um per o f a v e h ic le . B it e m ark s c a n b e i n clu ded h ere , a s w ell. O nly f o re n sic o do nto lo gis ts d eal w it h b it e m ark c o m paris o ns, b ut t h ese m ark s c a n b e c o nsid ere d m em bers o f t h e p a ern s f o r i n div id ualiz a on c a te go ry . B it e m ark s a re c o m plic a te d b eca u se d iﬀ ere n t n um bers o f t e eth m ig h t m ake t h em , t h ey a re f r e q uen tly o n c u rv e d s u rfa ce s t h at c a n c h an ge o r s h rin k, a n d i t i s d iﬃ cu lt t o p re p are t r u ly p ro per k n ow ns f o r c o m paris o n f r o m a s u sp ect’s t e eth . O ne c a n m ake m odels ( c a sts ) o f s o m eo ne’s t e eth , b ut i t i s n o t e asy t o r e p ro duce t h e e vid en ary m ark , b eca u se t h ey a re u su ally o n l iv in g s k in a n d t h e s u rfa ce s a re o en c u rv e d . U p u n l a ro und t e n y e ars a go , f o re n sic d en sts s o m e m es d ecla re d t h at a b it e m ark c o uld b e i n div id ualiz e d a n d c o uld i d en fy a p ar cu la r p ers o n. T h ere w ere a n um ber o f c a se s w here b it e m ark e vid en ce ﬁ gu re d i n a c rim in al c o nvic on.

O ne f a m ous e xa m ple o f t h ese c a se s o ccu rre d i n t h e F lo rid a t r ia l o f t h e s e ria l m urd ere r T e d B undy. T e d B undy w as o ne o f t h e m ost p ro liﬁ c s e ria l m urd ere rs i n U .S . h is to ry . H e i s k n ow n t o h ave k ille d d oze n s o f w om en i n W ash in gto n, O re go n, I d ah o, U ta h , C olo ra d o, a n d F lo rid a, a n d i n ve s ga to rs f a m ilia r w it h h im t h in k t h ere w ere m an y o th ers . H is e n re s to ry i s l o ng a n d c o m plic a te d , b ut t h e b it e m ark e vid en ce a ga in st h im c a m e i n t h e m urd er o f t w o C hi O m ega s o ro rit y s is te rs , a n d t h e a ssa u lt o n t w o o th ers , i n t h eir s o ro rit y h o use a t F lo rid a S ta te U niv e rs it y i n J a n uary , 1 978. T w o f o re n sic o do nto lo gis ts t e s ﬁed t h at t h e b it e m ark s o n t h e m urd ere d w om en w ere f r o m B undy. B undy w as e xe cu te d o n J a n uary 2 4, 1 989. L e ad in g u p t o h is e xe cu on, h e t a lk e d t o i n ve s ga to rs f r o m s e ve ra l o f t h e w este rn s ta te s w here h e h ad l iv e d ; h e c o nfe sse d t o a l o ng l is t o f m urd ers , s o m e o f w hic h t h e p o lic e h ad n’t e ve n k n ow n a b o ut. H e w as s u ch a s k ille d l ia r, h ow eve r, t h at p o lic e c o uld n eve r b e s u re h ow m an y v ic m s t h ere r e ally w ere . M ore r e ce n tly , h ow eve r, t h ere w ere a c o uple o f c a se s i n w hic h t h ere w as s a liv a a ro und t h e b it e m ark o n t h e v ic m , a n d l a te r D N A t y p in g s h ow ed t h at t h e s a liv a d id n o t m atc h t h e p ers o n w ho m t h e f o re n sic o do nto lo gis t h ad p o si ve ly i d en ﬁed . A s a r e su lt , b it e m ark s a re n o t g e n era lly a rib ute d t o a s p eciﬁ c p ers o n a n y m ore . I t i s m ore l ik e ly t h at a d en st w ill s a y t h at t h e p ers o n i s e xc lu ded , o r c o uld n o t b e e xc lu ded . T h in k A bo ut I t B it e m ark s a re n o l o nge r c o nsid ere d t o b e a w ay t o s p eciﬁ ca lly i d en fy s o m eo ne, b ut t h ey c a n b e u se d t o e xc lu de o r i n clu de a p ers o n o f i n te re st. D o y o u t h in k t h at i f T e d B undy w ere o n t r ia l t o day, t h e b it e m ark s w ould s ll b e a k e y p ie ce o f e vid en ce a ga in st h im ? I f y o u w ere t h e o do nto lo gis t t e s fy in g i n t h e t r ia l, h ow w ould y o u e xp la in t h e b it e m ark s t o t h e c o urt? I n div id ualiz a on T h e t e rm i n div id ualiz a on h as b een u se d f r e q uen tly i n t h is d is c u ssio n. T h e t e rm m ean s u niq uen ess— one o f a k in d— th e o nly o ne— to t h e e xc lu sio n o f a ll o th ers . R ece n tly , t h ere h as b een d is c u ssio n a m ong p a ern a n aly sts a b o ut w heth er u niq uen ess i s a r e alis c c o nclu sio n b ase d o n t h eir k n ow le d ge o f a n d e xp erie n ce w it h m an y o f t h ese p a ern s. H ow i s a n yo ne s u re t h ere i s n o c h an ce d uplic a te a n yw here ? T h ere h as b een a t r e n d i n t h e d ir e c on o f c h an gin g t h e t e rm in o lo gy t o d esc rib e p ers u asiv e m atc h es a s a s in gle s o u rc e ( P o ls k i e t a l. , 2 011). I f a p hra se l ik e a rib uta ble t o a s in gle s o u rc e w ere t o b e u se d a n d d eﬁ ned i n a n u nders ta n dab le w ay t h at s u gge ste d a s tro ng p o ssib ilit y o f i n div id ualit y o r c o m mon o rig in , b ut p erm i ed s o m e u nce rta in ty , i t c o uld b e a b e er r e ﬂ ec on o f t h e s ta te o f k n ow le d ge . E xp erim en ts o n p a ern m atc h in g w ill c o n nue, b ut i n t r u th t h ere i s n o w ay t o c o m pare a n y g iv e n p a ern w it h e ve ry p o ssib le s o urc e . E ve n i f a s in gle p a ern w ere s tu die d , f o r e xa m ple , a s tr ia on t o olm ark m ad e b y a s c re w driv e r o n a s c ra tc h ab le s u rfa ce , i t i s n early i m po ssib le t o r e p lic a te . T h e a n gle , t h e p re ssu re , t h e s p eed o f m ove m en t— th ese c o uld a ll a ﬀ ect t h e a p peara n ce o f t h e ﬁ nal m ark . A nd t h at i s o nly i n o ne s u rfa ce ! S o , w e h ave t o r e ly o n t h e s c ie n ﬁc c o nce p t o f i n duc on .

I f w e h ave g o od i n fo rm a on o n b asic p rin cip le s a b o ut a r e p re se n ta ve n um ber o f p o ssib le s it u a ons, w e c a n , b y i n duc ve l o gic , e xte n d t h em t o c o ve r a ll t h e m ark s i n t h at c a te go ry . E v e ry o ne i s f a m ilia r w it h t h e n o on o f u sin g ﬁ nge rp rin t e vid en ce t o e a s u sp ect t o a c rim e. D o y o u t h in k t h e i d ea o f ﬁ nge rp rin ts i s e ve r m is c o nstr u ed b y j u ro rs a s p art o f t h e C SI E ﬀ ect? J e ﬀ S ch rie r/ T h e S a gin aw N ew s/A sso cia te d P re ss C an y o u s e e t h e d iﬀ ere n ce s b etw een t h e ﬁ nge rp rin t p a ern s? W hic h p a ern i s o n y o ur ﬁ nge rs ? N ow t h at y o u k n ow t h e ﬁ nge rp rin t p a ern s o n y o ur ﬁ nge rs , e xa m in e t h em a ga in . C an y o u ﬁ nd e xa m ple s o f t h e k e y m in u a f e atu re s? T h e i d ea o f t h e u niq uen ess o f a n i n div id ual’s ﬁ nge rp rin ts g o es w ay b ack i n h is to ry , a s d em onstra te d b y T h o m as B ew ic k ’s u se o f h is t h um bprin t a s h is s ig n atu re m ark . M ic h ael N ic h ols o n /H is to ric a l/ C orb is 7 .4 Fin ge rp rin ts A m ong t h e o ld est a n d b est‐ e sta b lis h ed i n div id ualiz in g m ark in gs, ﬁ nge rp rin ts r e m ain o ne o f t h e m ost i m po rta n t t y p es o f p hysic a l e vid en ce i n t h e r e p erto ir e . A ﬁ nge rp rin t i m pre ssio n f r o m a s c e n e m atc h ed t o t h e k n ow n ﬁ nge rp rin t o f a s u sp ect e sse n ally p ro ve s t h at t h e p ers o n w as t h ere a t s o m e p o in t. A lm ost e ve ry o ne b elie ve s t h at ﬁ nge rp rin ts a re h ig h ly i n div id ual. I t h as b eco m e p art o f o ur u nsp o ke n c u lt u re . P e o ple t a lk a b o ut " D N A ﬁ nge rp rin ng" a n d u se t h e t e rm " u niq ue" t o d esc rib e a ﬁ nge rp rin t. F in ge rp rin ts a re a f o rm o f b io m etr ic i d en ﬁer, a b io lo gic a l m easu re m en t o r f e atu re o f a p ers o n t h at h as t h e p o te n al o f b ein g u se d a s t h e b asis f o r i n div id ualiz a on. O th er t y p es o f b io m etr ic i d en ﬁers i n clu de D N A; f a cia l f e atu re s; p arts o f t h e e ye , s u ch a s r e nas a n d i r is e s; a n d e ve n h an dw ri ng. T h ere i s i n te re st i n b io m etr ic s a s i n div id ualit y m ark e rs b eca u se t h ey a re d iﬃ cu lt t o r e p ro duce o r f o rg e . A ll d o cu m en ta ry i d en ﬁca on s y ste m s h ave b een s u bje ct t o f o rg e ry , i n clu din g d riv e r’s l ic e n se s, p assp o rts , c re d it a n d d eb it c a rd s, a n d e m plo ye e i d en fy in g c a rd s o r b ad ge s, m akin g i t p o ssib le f o r a c rim in al t o c h an ge h is o r h er i d en ty . T h is i s m ore d iﬃ cu lt a n d l e ss c o m mon w it h b io m etr ic m ark e rs . F in ge rp rin ts a re a n a ra c ve b io m etr ic b eca u se t h ey a re f o rm ed d urin g a p ers o n’s d eve lo pm en t i n t h e w om b, a re p erm an en t a n d u nch an gin g t h ro ugh o ut l if e , e asy t o r e co rd a n d s c a n u no btr u siv e ly , a n d i n vo lv e a b are m in im um o f p riv a cy i n va sio n t o r e co rd . S o m eth in g t o r e m em ber a b o ut t h e u se o f ﬁ nge rp rin ts a s b io m etr ic i d en ﬁca on v e h ic le s i s t h at t h e g o al i s n o t t o i n div id ualiz e t h e p ers o n a m ong e ve ry o ne i n t h e w orld . T h at i s n o t n ece ssa ry . A s y ste m m ig h t b e p ut i n p la ce t o d is ngu is h e m plo ye es w ho w ork i n a l a rg e , s e cu re d efe n se p la n t, o r e ve ry a ir lin e p asse n ge r w ho i s a f r e q uen t ﬂ ye r w it h U nit e d A ir lin es. I t i s p o ssib le t o d ete rm in e h ow m an y f e atu re s a n a u to m ate d s c a n nin g s y ste m h as t o d is ngu is h o n h ow m an y d iﬀ ere n t ﬁ nge rs t o t e ll a p art s o m e s p eciﬁ c n um ber o f p eo ple . T h e t h eo ry b eh in d t h is t e ch no lo gy i s , o f c o urs e , t h e b asis f o r a u to m ate d ﬁ nge rp rin t i d en ﬁca on s y ste m s. A nd, i t i s i m po rta n t i n g e ng a t t h e q ues on o f ﬁ nge rp rin t i n div id ualit y , b eca u se i t r e p re se n ts a n a u to m ate d m eth o d f o r c o m parin g l a rg e n um bers o f p rin ts f o r i n div id ual c h ara cte ris cs. N atu re o f F in ge rp rin ts T h e b egin nin g o f t h e r e co gn i on o f ﬁ nge rp rin ts a s a u niq ue p ers o nal i d en ﬁer i s s h ro uded i n t h e m is ts o f h is to ry . F in ge rp rin ts a re t h e r e su lt o f a t y p e o f s k in , f r ic on r id ge s k in , w hic h i s f o und o n t h e e n ds o f t h e ﬁ nge rs , i n t h e p alm s, a n d o n t h e s o le s o f t h e f e et o f p rim ate s, i n clu din g h um an s. T h o ugh p alm p rin ts a n d f o otp rin ts c a n b e c o m pare d a n d a n aly ze d , t h e m ost w ork h as b een d o ne o n ﬁ nge rp rin ts . A s s h ow n i n F ig u re 7 .2 , t h ere a re t h re e b asic ﬁ nge rp rin t p a ern s: a rc h es, l o ops, a n d w ho rls . F ig u re 7 .2 : T h re e b asic ﬁ nge rp rin t p a ern s A n i m po rta n t d eve lo pm en t i n t h e h is to ry o f ﬁ nge rp rin ts w as c la ssiﬁ ca on s y ste m s. C la ssiﬁ ca on s c h em es a re b ase d o n a ll t e n p rin ts f r o m a n i n div id ual. T h e b asic p a ern i s d ete rm in ed f r o m e ach p rin t a n d w it h in t h e b asic p a ern s, ﬁ nge rp rin ts h ave c e rta in r id ge f e atu re s t h at t h ey a ll s h are . F in ge rp rin t e xa m in ers c a ll t h ese f e atu re s m in u ae ( s in gu la r: m in u a) a n d t h re e o f t h em a re i m po rta n t t o ﬁ nge rp rin t e xa m in ers w hen t h ey c o m pare p rin ts . T h ese a re t h e d o t, t h e b if u rc a on, a n d t h e r id ge e n din g ( s e e F ig u re 7 .3 ). N ote t h at t h ese m in u ae c a n b e p re se n t i n m ore t h an o ne p la ce i n t h e p rin t p a ern , a n d t h at t h e l o ca on v a rie s f r o m p rin t t o p rin t. T h e t y p e, n um ber, a n d l o ca on o f m in u ae w it h in a p rin t f o rm t h e b asis o f i t s i n div id ualit y . F ig u re 7 .3 : K ey m in u a f e atu re s T h in k A bo ut I t C om pare t h e p a ern s a n d m in u ae o f y o ur ﬁ nge rp rin ts w it h f r ie n ds o r f a m ily m em bers . D o y o u s e e t h e d iﬀ ere n ce s? D o y o u t h in k ﬁ nge rp rin ts a re a n a ccu ra te a n d r e lia b le w ay t o i d en fy p eo ple ? C an F in ge rp rin ts b e A lt e re d ? H is to ry o f F in ge rp rin ts f o r I d en ﬁca on T h ere a re i n dic a ons f r o m a rc h ae o lo gic a l e xc a va ons t h at t h e u se o f ﬁ nge rp rin t a n d h an dprin t p a ern s a s m eth o ds o f p ers o nal i d en ﬁca on d ate s b ack t h o usa n ds o f y e ars ( B err y & S to ney, 2 001). T h ey a re t h o ugh t t o h ave b een u se d a s s ig n atu re s a n d m ark s o f a u th en cit y . T h e s tu dy a n d u se o f ﬁ nge rp rin ts a s u niq ue i d en ﬁers c a n b e t ra ce d t o t h e 1 7th a n d 1 8th c e n tu rie s i n E u ro pe. T h e E n glis h p la n t m orp ho lo gis t N eh em ia h G re w ( 1 641–1 712) p ublis h ed v e ry a ccu ra te d ra w in gs a n d d esc rip ons o f r id ge p a ern s i n a p ap er c a lle d " T h e D esc rip on a n d U se o f t h e P o re s i n t h e S kin o f t h e H an ds a n d F e et," i n t h e P hilo so p hic a l T ra nsa c on s o f t h e R oya l S o cie ty o f L o n don ( 1 684). T h en J o han nes E va n ge lis ta P u rk in je ( 1 787–1 869), a C ze ch p hysio lo gis t, w ro te a b o ut f r ic on r id ge p a ern s a n d d esc rib ed a n um ber o f ﬁ nge rp rin t p a ern s i n h is t h esis i n 1 823. T h o m as B ew ic k ( 1 753–1 828) w as p rim arily k n ow n a s a w ood e n gra ve r w ho se e n gra vin gs a p peare d i n b o oks. H e a p pears t o h ave " sig n ed " h is w ork w it h h is o w n t h um bprin t, b elie vin g i t t o b e a s u niq ue a s h is s ig n atu re . B ri sh c iv il s e rv a n ts i n I n dia , b egin nin g a ro und 1 850, w ere i m po rta n t c o ntr ib uto rs t o t h e d eve lo pm en t o f ﬁ nge rp rin ts a s a m ean s o f p ers o nal i d en ﬁca on. S ir W illia m H ers c h el, o ne s u ch p ers o n, i s o en c re d it e d w it h b ein g t h e ﬁ rs t E u ro pean t o r e co gn iz e t h e v a lu e o f ﬁ nge rp rin ts a s a m ean s o f i d en fy in g i n div id uals . D r. H en ry F a u ld s, a S co sh p hysic ia n , i s k n ow n t o h ave b een i n vo lv e d i n t h e s tu dy o f ﬁ nge rp rin ts a t l e ast b y 1 879. F a u ld s n o te d t h at ﬁ nge rp rin ts c o uld b e c la ssiﬁ ed a n d t h at r id ge d eta il a p peare d t o b e u niq ue, a n d h e m en oned t h e i d ea o f a p pre h en din g c rim in als b y l o ca ng ﬁ nge rp rin ts a t s c e n es. H e w ro te t o C harle s D arw in ( t h e s c ie n st r e sp o nsib le f o r p ro po sin g t h e t h eo ry o f e vo lu on) a b o ut ﬁ nge rp rin ts , w ho t h en f o rw ard ed t h e l e er o n t o F ra n cis G alt o n. G alt o n w as a w ell‐ k n ow n s c ie n st a n d e arly g e n e cs r e se arc h er, w ho h as b een s a id t o h ave p ut t h e s tu dy o f ﬁ nge rp rin ts o n s c ie n ﬁc f o o ng. G alt o n b eca m e i n te re ste d i n t h e s u bje ct o f ﬁ nge rp rin ts a n d p ut m uch t h o ugh t i n to ﬁ gu rin g o ut h ow t o s h ow t h at ﬁ nge rp rin ts w ere i n div id ual. F in ge rp rin t m in u ae a re s o m e m es c a lle d G alt o n f e a tu re s i n r e co gn i on o f h is c o ntr ib u ons. T h o m as T a ylo r, a U .S . D ep artm en t o f A gric u lt u re m ic ro sc o pis t, n o te d i n a s c ie n ﬁc j o urn al a r cle i n 1 877 t h at ﬁ nge rp rin ts a n d p alm p rin ts m ig h t b e u se d a s i d en ﬁca on f e atu re s, e sp ecia lly i n c rim in al m a ers . T o u nders ta n d a n d a p pre cia te h ow ﬁ nge rp rin ts c a m e i n to w id esp re ad u se , s o m e b ack g ro und o n a t e ch niq ue c a lle d a nth ro p om etr y i s n ece ssa ry . A nth ro po m etr y i n vo lv e s t h e m easu re m en t o f t h e h um an b o dy a n d i t s p arts , a n d c a n b e r e ga rd ed a s t h e ﬁ rs t r e co gn iz e d b io m etr ic i d en ﬁca on m eth o d. T h is m eth o d w as c re ate d b y A lp ho nse B er llo n ( 1 853–1 914) a n d l a id t h e f o unda on f o r t h e e ve n tu al a cce p ta n ce o f a b io m etr ic p ara m ete r a s a n o bje c ve b asis f o r p ers o nal i d en ﬁca on i n a l a w e n fo rc e m en t c o nte xt. B er llo n c a m e u p w it h t h is c o nce p t w hile w ork in g w it h t h e P aris P o lic e P re fe ctu re , w here h is d u es i n clu ded ﬁ llin g o ut a n d ﬁ lin g c rim in al i n fo rm a on c a rd s. T h e c rim in als w ere s k ille d a t a vo id in g i d en ﬁca on b y u sin g d is g u is e s a n d a lia se s. I t o ccu rre d t o B er llo n t h at i n div id ual p hysic a l f e atu re s c o uld b e u se d t o u niq uely i d en fy p eo ple o n c rim in al r e co rd s, a n d h e d eve lo ped a s y ste m o f m easu re m en ts t h at i n clu ded h ead s iz e , ﬁ nge r l e n gth , a n d s o f o rth , u l m ate ly c h o osin g 1 1 d iﬀ ere n t m easu re m en ts . T h e i n fo rm a on w as r e co rd ed o n ﬁ le c a rd s a n d a s y ste m w as d evis e d f o r o rg a n iz in g t h e ﬁ le s. H is s u perio rs d o ubte d t h e s y ste m , b ut i t s o on p ro ve d i t s v a lu e b y e n ab lin g t h e p o lic e t o i d en fy r e p eat a rre ste es e ve n i f t h ey p ro vid ed a lia s n am es. B er llo n e ve n tu ally b eca m e d ir e cto r o f t h e i d en ﬁca on b ure au o f t h e P aris P o lic e . P o lic e a ge n cie s i n m an y o th er p la ce s b ega n t o u se h is s y ste m — o en c a lle d B er llo n age .

I t s u l m ate u ndo in g w as t h e u neq uiv o ca l p ro of t h at d iﬀ ere n t i n div id uals c o uld h ave t h e s a m e a n th ro po m etr ic m easu re m en ts . A w ell‐ k n ow n e xa m ple o f t h is c h an ce d uplic a on c a m e a t t h e L e ave n w orth P ris o n i n t h e U .S . A n ew p ris o ner n am ed W ill W est w as h avin g h is m easu re m en ts t a ke n w hen a s ta ﬀ m em ber b ega n t o s u sp ect t h at h e h ad e n co unte re d t h is p ro ﬁ le b efo re . U po n i n ve s ga on, h e f o und t h at t h e s a m e m easu re m en ts ﬁ t a m an n am ed W illia m W est w ho w as a lr e ad y i n ca rc e ra te d a t t h e p ris o n ( a n d u nre la te d t o W ill W est, a lt h o ugh t h ey l o oke d a l o t a lik e ). H ow eve r, t h e t w o d id h ave d iﬀ ere n t ﬁ nge rp rin ts . T h is i n cid en t, a n d o th ers l ik e i t , e ve n tu ally c o nvin ce d p o lic e i d en ﬁca on s p ecia lis ts t h at ﬁ nge rp rin ts r e p re se n te d t h e b asis f o r a s u perio r m eth o d o f p ers o nal i d en ﬁca on. A ro und 1 893, t h e B ri sh H om e O ﬃ ce , p are n t a ge n cy o f t h e L o ndo n M etro po lit a n P o lic e ( S co tla n d Y a rd ), d ecid ed t o a d d ﬁ nge rp rin ts t o t h e B er llo n c a rd s f o r c rim in als i n t h eir i d en ﬁca on s y ste m . B efo re l o ng, t h e s u cce ss o f ﬁ nge rp rin ts o ve rs h ad ow ed t h at o f B er llo nage i n c rim in al i d en ﬁca on, a n d a n th ro po m etr y w as a b an do ned i n 1 901. S ir E d w ard H en ry ( 1 850–1 931) w as a m em ber o f t h e B ri sh I n dia n C iv il S e rv ic e , b egin nin g i n a b o ut 1 873. I n 1 891, h e b eca m e i n sp ecto r g e n era l o f p o lic e f o r B en ga l p ro vin ce , w here a n th ro po m etr y w as i n u se f o r c rim in al i d en ﬁca on. H e b eca m e i n te re ste d i n ﬁ nge rp rin ts , r e ad G alt o n’s b o ok, a n d c o rre sp o nded w it h a n d l a te r v is it e d h im . G alt o n s h are d a ll t h e i n fo rm a on h e h ad a b o ut ﬁ nge rp rin ts w it h H en ry , i n clu din g m ate ria ls h e h ad o bta in ed f r o m H ers c h el a n d F a u ld s. H en ry i s w id ely k n ow n f o r w ork in g o ut a ﬁ nge rp rin t c la ssiﬁ ca on s y ste m t h at w as a d o pte d i n B ri sh I n dia , a n d p re se n te d t o p eo ple i n t h e U .K . i n 1 899. H e w ro te a c la ssic b o ok e n tle d C la ssiﬁ ca on a nd U se s o f F in gerp rin ts . J u an V uce ch ( 1 858–1 925) w as t h e w este rn h em is p here ’s ﬁ nge rp rin t p io neer. A n e m plo ye e o f t h e p o lic e d ep artm en t i n L a P la ta , A rg e n na, h e b eca m e c o nvin ce d o f t h e v a lu e o f ﬁ nge rp rin ts a s a m ean s o f c rim in al i d en ﬁca on a n d w ro te a b o ok o n t h e s u bje ct i n 1 894. B y 1 896, t h e A rg e n ne p o lic e h ad a b an do ned B er llo nage i n f a vo r o f ﬁ nge rp rin ts i n c rim in al r e co rd s. T h e ﬁ rs t r e co rd ed c a se i n w hic h ﬁ nge rp rin ts w ere u se d t o s o lv e a c rim e t o ok p la ce i n A rg e n na i n 1 892. A w om an n am ed F ra n cis c a R o ja s a lle ge d t h at h er t w o c h ild re n w ere m urd ere d b y a m an n am ed V ela sq uez. I n ve s ga to rs e xa m in ed h er h o m e a n d f o und a b lo ody t h um b p rin t o n t h e b ed ro om d o or. V uce ch c o m pare d t h e ﬁ nge rp rin ts o f R o ja s a n d V ela sq uez t o t h e b lo ody ﬁ nge rp rin t, a n d f o und i t b elo nge d t o R o ja s, l in kin g h er t o t h e m urd er o f h er c h ild re n . V uce ch d evis e d a c la ssiﬁ ca on s y ste m f o r ﬁ nge rp rin ts t h at w as u se d i n A rg e n na a n d t h ro ugh o ut S o uth A m eric a . I n N orth A m eric a , ﬁ nge rp rin ts w ere i n u se b y t h e N ew Y o rk C it y c iv il s e rv ic e ( t o p re ve n t i m pers o na ons d urin g e xa m in a ons) b y 1 903, a n d ﬁ nge rp rin ts w ere i n tro duce d a b o ut t h e s a m e m e i n t h e N ew Y o rk S ta te p ris o n s y ste m a n d a t t h e L e ave n w orth P e n it e n ary . A n um ber o f p o lic e d ep artm en ts b ega n u sin g ﬁ nge rp rin ts a s i d en ﬁers i n c rim in al r e co rd s a s w ell. T h e 1 904 S t. L o uis W orld ’s F a ir p ro vid ed t h e v e n ue f o r a c h an ce m ee ng b etw een I n sp ecto r E d w ard F o ste r o f t h e R oya l C an ad ia n M ounte d P o lic e a n d D ete c ve J o hn F e rrie r o f S co tla n d Y a rd . A s a r e su lt o f w hat h e l e arn ed i n S t. L o uis , F o ste r c o nvin ce d h is s u perio rs i n t h e R .C .M .P . o f t h e u lit y o f ﬁ nge rp rin ts . I n 1 910, a m an c a lle d T h o m as J e n nin gs w as a rre ste d i n C hic a go a n d b ro ugh t t o t r ia l f o r m urd er. T h e p rim ary e vid en ce a ga in st h im w as ﬁ nge rp rin ts . T h e s ta te w an te d t o e n su re t h at t h e ﬁ nge rp rin t i d en ﬁca on e vid en ce w ould s u rv iv e t h e a n cip ate d a p peal t o t h e I llin o is S u pre m e C ourt, a n d t h ey c a lle d E d w ard F o ste r a s a n e xp ert w it n ess. T h e d efe n dan t w as c o nvic te d , t h e e vid en ce d id s u rv iv e , a n d t h e J e n nin gs c a se i s c o nsid ere d a l a n dm ark ﬁ nge rp rin t c a se i n c rim in al j u ris p ru den ce . F in ge rp rin t I d en ﬁca on O rg a n iz a ons N ow t h at ﬁ nge rp rin ts h ave b eco m e a m ajo r b io m etr ic i n dic a to r a n d p la y a n i m po rta n t r o le i n c rim in al i n ve s ga ons, t h ere a re a c o uple o f i m po rta n t o rg a n iz a ons t h at ﬁ nge rp rin t e xa m in ers m ay c h o ose t o b eco m e a p art o f. T h e I n te rn a onal A sso cia on f o r I d en ﬁca on ( IA I) i s t h e p rim ary p ro fe ssio nal o rg a n iz a on f o r ﬁ nge rp rin t e xa m in ers . I t h as e xte n siv e c e r ﬁca on p ro gra m s a n d i t s l a te n t p rin t c e r ﬁca on i s d iﬃ cu lt t o o bta in . M an y p hysic a l p a ern c o m paris o n s p ecia lis ts a ls o b elo ng t o t h e I A I. A no th er i m po rta n t g ro up i s t h e S cie n ﬁc W ork in g G ro up o n F ric on R id ge A naly sis , S tu dy a n d T e ch no lo gy ( S W GFA ST ). T h is c o m mi ee i s a c o nse n su s s ta n dard s e ng b o dy f o r a ll c o m paris o ns i n vo lv in g f r ic on r id ge s k in ( ﬁ nge rp rin ts , f o otp rin ts , p alm p rin ts , e tc .) . I t h as a lr e ad y a d o pte d a n um ber o f c o nse n su s s ta n dard s, i n clu din g s ta n dard s f o r a ssig n in g s in gle s o urc e a rib u on. F in ge rp rin t C la ssiﬁ ca on a n d F ile S to ra ge W hen a ll ﬁ nge rp rin t r e co rd s c o nsis te d o f i n ke d i m pre ssio ns o n a t e n ‐p rin t c a rd , a c la ssiﬁ ca on s y ste m w as v e ry i m po rta n t. H ow e ls e c o uld t h e c a rd s b e ﬁ le d s o t h at t h ey w ere e asily f o und? C la ssiﬁ ca on w as b ase d o n a t e n ‐p rin t c a rd , n o t o n a s in gle p rin t. Y o u n eed ed a ll t e n p rin ts f r o m a p ers o n t o c la ssif y t h e p rin ts . I n m ost c rim in al c a se s w here ﬁ nge rp rin ts a re r e co ve re d , t h ere i s o nly o ne— or s o m e m es o nly a p ar al— im pre ssio n o f o ne ﬁ nge r. I n s u ch a c a se , h ow w ould y o u l o ca te i t i n y o ur c a rd ﬁ le ? S im ply p ut, y o u c o uld n’t , w hic h w as t h e p ro ble m . S o m e m es, t h ere m ig h t b e o ne o r m ore s u sp ects , a n d t h eir ﬁ nge rp rin ts c o uld b e p ulle d f o r c o m paris o n. B ut i f t h ere w ere n ’t a n y s u sp ects , t h ere w as n o r e alis c w ay t o s e arc h d ra w ers t h at w ere f u ll o f ﬁ le s t o l o ok f o r o ne ﬁ nge rp rin t. T h at i s w hy t h e a d ve n t o f a u to m ate d ﬁ nge rp rin t i d en ﬁca on s y ste m s ( A FIS ) r e vo lu oniz e d t h e u se o f ﬁ nge rp rin ts . T h e s y ste m c o nsis ts o f a s c a n ner t h at r e co rd s i m age s o f a ll t e n p rin ts a n d s to re s t h em o n a s e rv e r. I t i n clu des m an y w ork sta ons f r o m w hic h o pera to rs c a n e n te r n ew ﬁ nge rp rin ts , a n d s e arc h t h e s y ste m f o r e xis ng o nes. T h e w ay i n w hic h t h e s y ste m w ork s i s r e la ve ly s im ple . T h e e xa m in er b egin s b y s c a n nin g a ﬁ nge rp rin t a n d c o m pute riz e d a lg o rit h m s m ark t h e m in u ae t o s e arc h f o r. T h e c o m pute r t h en c a lc u la te s a s c o re b ase d u po n t h e d egre e o f m atc h . M ost o f t h e m e, t h e m atc h in g p rin t w ill a p pear i n t h e ﬁ rs t f e w e n tr ie s, i f i t i s i n t h e s y ste m . T h e e xa m in er m ust p ull u p t h e l ik e ly m atc h es a n d c o m pare t h em w it h t h e ﬁ nge rp rin t i n q ues on. T h e c o m pute r i s n o t u se d f o r t h e p urp o se s o f m atc h in g p rin ts f o r c o urt p urp o se s. T h at i s s o m eth in g o nly a n e xa m in er c a n d o . A FIS i s u se d t o p ro vid e p o ssib le m atc h es, h elp in g n arro w d ow n t h e l is t o f i n div id uals t h e ﬁ nge rp rin t c o uld b elo ng t o . A n e xa m in er w ill t h en n eed t o c o m pare t h e ﬁ nge rp rin t a n d t h e p o ssib le m atc h es p ro vid ed t o m ake t h e ﬁ nal d ecis io n o n t h e i d en ﬁca on o f t h e ﬁ nge rp rin t. T h in k A bo ut I t D o y o u t h in k t h at t e n ‐p rin t c a rd s a n d/o r A FIS s y ste m s a re a g o od w ay t o o rg a n iz e a n d s to re ﬁ nge rp rin t d ata ? W hat o th er w ays c a n y o u t h in k o f t h at c o uld i m pro ve t h e ﬁ lin g s y ste m ? F in ge rp rin t c o lle c on d o ne t h e o ld ‐f a sh io ned w ay c o nsis te d o f i n kin g e ach i n div id ual ﬁ nge r a n d o rg a n iz in g t h e i m pre ssio ns o nto a s in gle c a rd . H ow h as m odern t e ch no lo gy i m pro ve d t h is p ro ce ss? i S to ck p hoto /T h in ksto ck I f ﬁ nge rp rin ts a re t o b e f o und a t t h e s c e n e o f a c rim e, t h ey a re m ost l ik e ly t o b e l a te n t o nes f o und a er a n i n ve s ga to r h as d uste d f o r ﬁ nge rp rin ts . J o e J o h nsto n /T h e T rib une ( o f S a n L u is O bis p o)/ A sso cia te d P re ss D on R ya n/A sso cia te d P re ss 7 .5 C olle c on a n d P re se rv a on o f F in ge rp rin ts T h ere a re t w o t o pic s t h at m ust b e c o nsid ere d i n t e rm s o f c o lle c ng a n d p re se rv in g ﬁ nge rp rin ts f o r a c a se . T h e ﬁ rs t i s c o lle c ng o r t a kin g ﬁ nge rp rin ts f r o m k n ow n i n div id uals . T h e s e co nd i s c o lle c ng ﬁ nge rp rin ts f r o m c rim e s c e n es a n d o bje cts . C o lle c on a n d P re se rv a on o f K n ow ns A t o ne m e, ﬁ nge rp rin ts w ere t a ke n f r o m k n ow n i n div id uals b y i n kin g t h e ﬁ nge rs a n d i m pre ssin g t h em o nto ﬁ nge rp rin t c a rd s. I n a d di on t o i n clu din g a l a b ele d b ox f o r e ach ﬁ nge r, t h ere w as s p ace o n t h e b o om o f t h e c a rd t o r e p rin t t h e t h um bs, a n d t o i m pre ss t h e f o ur ﬁ nge rs o f e ach h an d. T h ese i m pre ssio ns s e rv e d a s b ack‐u ps i f t h e m ain b oxe d i m pre ssio ns w ere n o t o f h ig h e n o ugh q ualit y f o r a c o m paris o n. F in ge rp rin ts f r o m t h ese t e n ‐p rin t c a rd s c a n b e s c a n ned i n to A FIS s y ste m s t o b uild t h e s in gle p rin t d ata b ase s. T o day, m ost ﬁ nge rp rin ts a re c o lle cte d b y L iv e S ca n t e ch no lo gy. T h e p ers o n p la ce s e ach ﬁ nge r ( a n d t h um b) o nto a s m all s c a n nin g p la te . S o m e m es, t h ere i s a n o n‐s c re en g u id e t o h elp t h e p ers o n a d ju st t h e p o si on a n d p re ssu re o f e ach ﬁ nge r. T h e d evic e t h en s c a n s t h e p rin ts d ir e ctly i n to a n A FIS . T h ese d evic e s c a n b e s e en a t p o rts o f e n tr y i n to t h e U nit e d S ta te s, s u ch a s i n i n te rn a onal a ir p o rts . F in ge rp rin ts a re a ls o p re se rv e d e le ctro nic a lly . T h e l a rg e st d ata b ase o f ﬁ nge rp rin ts i s c o nta in ed i n t h e F B I’s i n te gra te d A FIS ( IA FIS ) s y ste m . T h e s y ste m c o nta in s o ve r 7 0 m illio n p rin t ﬁ le s f r o m c rim in al h is to rie s, a n d a b o ut 3 5 m illio n o th er ﬁ le s. P e o ple w ho a re a rre ste d a re ﬁ nge rp rin te d . B ut m an y o th er p eo ple m ay b e ﬁ nge rp rin te d a s w ell, l ik e t h o se w ho h ave ﬁ re arm s p erm it s o r s e cu rit y c le ara n ce s o r h ave u nderg o ne b ack g ro und c h eck s f o r a v a rie ty o f r e aso ns. C o lle c on, P re se rv a on, a n d P ro ce ssin g o f E v id en ary P rin ts C olle c ng ﬁ nge rp rin ts f r o m s c e n es i s s im ila r t o c o lle c ng e vid en ce f r o m a s c e n e, b ut i t i s m ore c o m plic a te d t h an c o lle c ng k n ow n p rin ts . S o m e m es, p rin ts a t s c e n es a re v is ib le , b ut o en t h ey a re n o t. T h e o nes w hic h a re n o t r e q uir e s o m e s o rt o f d eve lo pm en t o r p ro ce ssin g t o r e n der t h em v is ib le . T h e ﬁ rs t d ecis io n a n i n ve s ga to r m ust m ake i s w heth er t o u se d eve lo pm en t ( v is u aliz a on) t e ch niq ues f o r p rin ts a t t h e s c e n e, o r b rin g t h e o bje ct b earin g t h e p rin t b ack t o t h e l a b . T h e l a rg e r a n d m ore u nm ova b le t h e o bje ct o r s u rfa ce , t h e m ore l ik e ly a n i n ve s ga to r w ould e m plo y d eve lo pm en t t e ch niq ues i n t h e ﬁ eld . A er l o ca ng a n d/o r d eve lo pin g t h e p rin t o r p rin ts , t h e c rim e s c e n e p ro ce sso r m ust e it h er c o lle ct t h e w ho le o bje ct t h e p rin t r e sid es o n, o r c o lle ct t h e ﬁ nge rp rin t a lo ne. P h o to gra p hy a n d s k e tc h es a re u se d t o d o cu m en t t h e l o ca on o f t h e ﬁ nge rp rin t, o r t h e o bje ct c o nta in in g i t , a t t h e s c e n e. T h e p rin t o r d eve lo ped p rin t m ust a ls o b e p ho to gra p hed . I t i s b est i f t h e p ho to c a n b e 1 :1 ( lif e s iz e i m age ). T h at w ay t h ere i s n o c o m pre ssio n o f t h e d eta ils . I f a p rin t h as r e q uir e d d eve lo pm en t, i t m ay b e p o ssib le t o t a p e l i t h e p rin t, d ep en din g o n t h e t y p e o f d eve lo pm en t. A ll t h e u su al r u le s a b o ut c h ain o f c u sto dy p erta in h ere . T h e i t e m b earin g t h e p rin t o r t h e t a p e l i m ust b e c a re fu lly p ack a ge d , l a b ele d , a n d s e ale d . I t e m s h ave t o b e p ack a ge d s o a s t o p ro vid e m axim um p ro te c on o f a n u ndeve lo ped p rin t i m pre ssio n. N oth in g s h o uld t o uch o r r u b t h e i m pre ssio n d urin g s to ra ge o r t ra n sp o rt. S o m e t y p e o f w ood o r p la s c t ro ugh w ould h ave t o b e u se d t o p ro te ct t h e r id ge i m pre ssio ns f r o m t h e p ack a ge d urin g t ra n sp o rt. D eve lo ped l a te n ts m ust a ls o b e p ro te cte d . T a p e l i s a re p la ce d o nto b ack in gs, a n d a re t h us p ro te cte d . T h ere a re t h re e k in ds o f ﬁ nge rp rin t i m pre ssio ns e n co unte re d : v is ib le , p la s c , a n d l a te n t . V is ib le F in g erp rin ts V is ib le p rin ts a re a ls o s o m e m es c a lle d p ate n t .

V is ib le p rin ts a re m ad e i n d ir t, i n k, b lo od, o r s o m e o th er m ed iu m t h at i s v is ib le t o t h e e ye . T h ese w ould b e p ho to gra p hed a n d, i f p o ssib le , t h e o bje ct o n w hic h t h ey a re d ep o sit e d w ould b e c o lle cte d . P la s c F in g erp rin ts P la s c p rin ts a re t h re e‐d im en sio nal a n d a re m ad e i n s o r e ce iv in g m ate ria ls l ik e s illy p u y o r t a r. T h ese a re i n den ta on p rin ts . T h ey a re ﬁ rs t p ho to gra p hed . T h en , t h e o bje ct b earin g t h e p rin t i s c o lle cte d , i f p o ssib le . I f n o t, t h is t y p e o f ﬁ nge rp rin t i m pre ssio n c a n b e c a st i n t h e s a m e m an ner a s f o otw ear i n den ta ons, o nly t h e c a s ng m ate ria ls a re s ilic o ne‐b ase d a n d c a p ab le o f c a p tu rin g ﬁ ne d eta il m uch b e er t h an a n y t y p e o f p la ste r. T h in k A bo ut I t W hat d o t h e t e ch niq ues a n d p ro ce d ure s f o r e vid en ary ﬁ nge rp rin t c o lle c on a n d p re se rv a on h ave i n c o m mon w it h t h e c o lle c on a n d p re se rv a on t e ch niq ues f o r o th er p a ern e vid en ce ? W hat a re t h e d iﬀ ere n ce s? L a te n t F in g erp rin ts L a te n t ﬁ nge rp rin ts c a n no t b e c le arly s e en o r v is u aliz e d w it h o ut s o m e d eve lo pm en t o r p ro ce ssin g. T h ere a re t h re e b asic m eth o ds o f p ro ce ssin g o r d eve lo pin g l a te n t ﬁ nge rp rin ts : p hysic a l, c h em ic a l, a n d i n str u m en ta l. T h e m ost c o m mon a n d f a m ilia r p hysic a l m eth o d i s p ow der d us ng. H ere , a ﬁ nge rp rin t p ow der ( u su ally b la ck ) i s a p plie d w it h a ﬁ ne b ru sh t o t h e l a te n t p rin t r e sid ue. T h e p ow der p ar cle s a d here t o t h e f a y c o m po nen ts i n t h e r e sid ue a n d m ake t h e r id ge s v is ib le . A no th er t e ch niq ue u se d i s c a lle d m agn a‐b ru sh . H ere a s m all m agn et i s u se d t o a p ply m agn e c p ar cle s t o t h e p rin t r e sid ue. T h ese p ar cle s a d here t o t h e l a te n t r e sid ue t h e s a m e w ay a s t h e p ow der p ar cle s. P o w der‐d uste d ( in clu din g m agn a‐p ow der d uste d ) p rin ts c a n g e n era lly b e l i ed u sin g t ra n sp are n t t a p e. T h e t a p e m ust b e p la ce d c a re fu lly o nto t h e d uste d p rin t t o a vo id a n y a ir b ubble s. T h is c a n b e d o ne w it h a r u bber r o lle r. T h e t a p e i s l i ed a ll i n o ne s lo w m o on, a n d t h e t ra n sp are n t t a p e l i i s t h en p la ce d o nto a c o ntra s ng b ack g ro und, s u ch a s a w hit e s u rfa ce . A no th er m ore c o m ple x t e ch niq ue u se s m oly b den um d is u lﬁ de p ar cle s i n a s o lu on. T h is i s k n ow n a s " sm all p ar cle r e age n t" a n d w ork s o n s u rfa ce s t h at a re w et. L i in g o f a s m all p ar cle r e age n t d eve lo ped p rin t c a n b e a cco m plis h ed w it h o ut l e ng t h e s u rfa ce d ry i f t h e t a p e i s c a re fu lly a p plie d t o t h e c e n te r a n d p re ssu re a p plie d i n a ll d ir e c ons o utw ard , p ush in g a w ay t h e l iq uid d ro ple ts i n t h e p ro ce ss. L a te n ts o n w et s u rfa ce s a re n ’t c o m mon, b ut t h e s it u a on d o es a ris e . T h in k o f a c a n o f b eer w it h a l a te n t o n i t , t a ke n f r o m t h e r e fr ig e ra to r a n d a llo w ed t o s it o ut i n a h um id e n vir o nm en t f o r a w hile w here w ate r c a n c o nden se o nto i t . T h e c la ssic a l c h em ic a l t e ch niq ues f o r p rin t d eve lo pm en t w ere s ilv e r n it ra te , i o din e f u m in g, n in hyd rin , a n d s u per g lu e .

S ilv e r n it ra te d eve lo pm en t w ork s o n t h e s a m e p rin cip le a s t h e d eve lo pm en t o f p ho to gra p hic ﬁ lm , w here s ilv e r c h lo rid e i s c h em ic a lly r e d uce d t o m eta llic s ilv e r. I o din e f u m in g i s b ase d o n i o din e m ole cu le s g o in g f r o m s o lid t o v a p o r w it h o ut b eco m in g l iq uid ( a p ro ce ss c a lle d s u blim a on). T h e i o din e v a p o r c a n i n te ra ct w it h ﬁ nge rp rin t r e sid ue a n d g iv e i t a t e m po ra ry c o lo r. T h e c o lo r c a n b e m ad e p erm an en t w it h o th er c h em ic a ls . N eit h er s ilv e r n it ra te n o r i o din e a re u se d f o r l a te n t p rin ts a n ym ore b eca u se t h e o th er t e ch niq ues a re b e er o r e q uiv a le n t. S ilv e r h as g o en e xp en siv e , a n d i t c re ate s a d is p o sa l p ro ble m a er u se . O th er t e ch niq ues a re b e er t h an i o din e b eca u se t h ey h ave t h e p o te n al f o r g re ate r s e n si vit y . T o day, n in hyd rin o r s u per g lu e t r e atm en t i s f o llo w ed b y a n a d di onal t r e atm en t w it h o th er c h em ic a ls t o m ake t h e v is u aliz a on m ore s e n si ve — th at i s , l e sse r a m ounts o f r e sid ue c a n b e d ete cte d . N in hyd rin i s a c h em ic a l t h at r e acts w it h t h e a m in o a cid s i n ﬁ nge rp rin t r e sid ue. A m in o a cid s a re t h e b uild in g b lo ck s o f p ro te in s. S u per g lu e c a n b e f u m ed o nto ﬁ nge rp rin t r e sid ue w here i t r e acts t o f o rm a s e m is o lid , w hi sh d ep o sit o n t h e r id ge p a ern s. S u per g lu e w ill v a p o riz e b y i t s e lf , a n d t h e p ro ce ss c a n b e a cce le ra te d w it h h eat. T h e v a p o rs , o r f u m es, i n te ra ct w it h t h e ﬁ nge rp rin t r e sid ue. T h e s u per g lu ed ﬁ nge rp rin t i s f a ir ly p erm an en t, b ut c a n b e p ow der d uste d , a n d t h e d uste d p rin t l i ed . T h is i s d o ne i n t h e s a m e w ay a s l i in g d uste d ﬁ nge rp rin ts a s d esc rib ed e arlie r. S u per g lu ed p rin ts c a n a ls o b e f u rth er t r e ate d w it h o th er c h em ic a ls b y d ip pin g o r s p ra yin g t o m ake t h e v is u aliz a on m ore s e n si ve . N in hyd rin i s t h e m eth o d o f c h o ic e f o r a b so rb en t s u rfa ce s l ik e p ap er o r s h eet r o ck . S u per g lu e w ill w ork o n p ra c ca lly a n y s u rfa ce . T h e m ost c o m mon i n str u m en ta l t e ch niq ue i s c a lle d l a se r i llu m in a on. W it h t h is p ro ce ss, ﬁ nge rp rin ts a re c o m monly d eve lo ped w it h s u per g lu e, o n w hic h a c h em ic a l c a lle d l a se r d ye i s a p plie d . W hen a l a se r i s s h in ed o n a ﬁ nge rp rin t p ro ce sse d i n t h is w ay, a v e ry s m all a m ount o f r e sid ue c a n b e v is u aliz e d , a n d t h en p ho to gra p hed . S o m e m es, l a se r i llu m in a on i s u se d d ir e ctly o n ﬁ nge rp rin t r e sid ues, b ut t h is t e ch niq ue i s u se d l e ss f r e q uen tly . L a se r p ro ce d ure s a re u su ally p erfo rm ed i n t h e l a b . P o rta b le l a se rs d o e xis t, b ut t h ese t e ch niq ues a re v e ry c u m bers o m e i n t h e ﬁ eld . L a se r‐illu m in ate d p rin ts w ould t y p ic a lly b e p ho to gra p hed f o r c o m paris o n. T h e l a se r d ye p ro ce d ure i s i n dic a te d i f t h e r id ge p a ern s a re n o t c le ar e n o ugh f o r a c o m paris o n f o llo w in g s u per g lu e a lo ne. F in ge rp rin ts i n b lo od c a n b e a s p ecia l c a se . S o m e m es, t h ey a re p la in ly v is ib le ( in t h ese c a se s t h ese w ould b e c o nsid ere d v is ib le p rin ts ), b ut a t o th er m es t h ey m ay r e q uir e s p ecia l e n han ce m en t t e ch niq ues. T h e e n han ce m en t p ro ce d ure s m ake u se o f c h em ic a ls t h at p ro duce c o lo r i n t h e p re se n ce o f b lo od. T h ey a ls o c o nta in a s ck y s u bsta n ce t o m ake t h em a d here t o t h e r e sid ue a n d a r a p id ly e va p o ra ng s o lv e n t s o t h at b lo ody p rin ts o n a v e r ca l s u rfa ce d o n’t r u n w hen t h e c h em ic a l i s s p ra ye d . T h ese e n han ce m en t t e ch niq ues h ave t h e p o te n al o f i n te rfe rin g w it h D N A p ro ﬁ lin g o f t h e b lo od a s t h e c h em ic a ls i n t h e e n han ce m en t m ix tu re c a n a d ve rs e ly a ﬀ ect D N A. I t i s i m po rta n t f o r i n ve s ga to rs t o c o nsid er t h e v a lu e o f D N A p ro ﬁ lin g a n d ﬁ nge rp rin t i d en ﬁca on t o t h e c a se i n t h ese s it u a ons. A s m all s p ecim en o f b lo od c o uld b e c o lle cte d , f o r e xa m ple , w it h o ut d is tu rb in g t h e r id ge p a ern s a ﬁ nge rp rin t e xa m in er w ould n eed . T h in k A bo ut I t I f y o u h ad t o c h o ose a s in gle m eth o d f o r p ro ce ssin g l a te n t p rin ts i n t h e l a b o ra to ry , w hic h o ne w ould y o u c h o ose , a n d w hy? 7 .6 A naly sis o f F in ge rp rin ts F o r f o re n sic a n d l e ga l p urp o se s, ﬁ nge rp rin t a n aly sis o r c o m paris o ns a re t h e h eart o f t h e m a er. T h e c o m paris o n o f a q ues oned p rin t w it h a k n ow n, a n d t h e a b ilit y t o f o rm a n u neq uiv o ca l c o nclu sio n, m ake ﬁ nge rp rin ts v a lu ab le a s e vid en ce . T ra in ed e xa m in ers c o m ple te t h e c o m paris o ns. T h e t ra in in g i s l e n gth y. I t c a n t a ke u p t o t w o y e ars b efo re a n ew e xa m in er i s a llo w ed t o o pera te w it h o ut s u perv is io n. T h ere i s a s p eciﬁ c p ro to co l t o b e c o m ple te d f o r e ach c o m paris o n. T h e ﬁ rs t t h in g t o b e d ecid ed i s w heth er t h e p rin t i s s u it a b le f o r c o m paris o n. T h is d ecis io n i s b ase d o n t h e c la rit y o f t h e r id ge s a n d t h e e xa m in er’s j u dgm en t t h at a p ro per c o m paris o n c a n b e c o m ple te d . F o r e xa m ple , t h e e xa m in er m ust d ete rm in e i f t h ere i s e n o ugh o f t h e p rin t p re se n t i n t h e i m pre ssio n a n d i f t h ere a re e n o ugh v is ib le d eta ils ( m in u ae ). T h e e xa m in er m ust a ls o d ete rm in e i f t h e p rin t i s e asily v ie w ed , i s n o t s m udge d , a n d d o es n o t h ave t o o m an y i m pre ssio ns o ve rla id o n o ne a n o th er. I f t h e p rin t i s j u dge d t o b e u nsu it a b le f o r c o m paris o n, t h e e xa m in a on e n ds. I f t h e p rin t i s j u dge d t o b e s u it a b le , t h e q ues oned p rin t m ust b e p ro perly o rie n te d f o r c o m paris o n w it h a k n ow n ( a w ho le ﬁ nge rp rin t). T o p erfo rm a n a ccu ra te e xa m in a on, t h e p rin t c a n no t b e u psid e d ow n o r r o ta te d 9 0 d egre es. N ext, i t g o es t h ro ugh a n aly sis , c o m paris o n, e va lu a on, a n d v e riﬁ ca on ( A CE‐V ) .

A naly sis c o nsis ts o f j u dgin g s u it a b ilit y , a rra n gin g c o rre ct o rie n ta on, a n d j u dgin g t h e m in u ae c o nte n t o f t h e p rin t. T h e c o m paris o n p art i s c a re fu lly ﬁ gu rin g o ut i f e ve ry m in u a f e atu re i n t h e q ues oned i m pre ssio n i s a ls o i n t h e k n ow n, a n d i n t h e s a m e l o ca on. T h e e va lu a on s te p i s b ase d o n t h e e xa m in er’s k n ow le d ge o f a n d e xp erie n ce w it h p rin t c o m paris o ns. H ow c o m mon o r r a re i s t h is p a ern ? I f t h e e xa m in er i s s a sﬁ ed t h at t h ere i s e n o ugh d eta il, a n d t h ere a re n o u nexp la in ed d iﬀ ere n ce s b etw een t h e q ues oned a n d k n ow n, a n i d en ﬁca on c a n b e m ad e. I n t h e v e riﬁ ca on s te p , a n o th er e xa m in er i s a sk e d t o l o ok a t t h e p rin ts a n d v e rif y t h e ﬁ rs t e xa m in er’s c o nclu sio n. A s s h ow n i n T a b le 7 .1 , t h e m ain c a te go ry t o w hic h t h e ﬁ nge rp rin t b elo ngs ( a rc h , l o op, w ho rl, e tc .) , i s s o m e m es c a lle d F ir s t L e ve l, o r L e ve l 1 . T h e m in u ae p re se n t a n d t h eir l o ca on i s s o m e m es c a lle d S e co nd L e ve l, o r L e ve l 2 . T h ere i s a L e ve l 3 a s w ell, c o nsis ng o f p o re s a n d r id ge f e atu re s. L e ve l 3 i s n o t a lw ays u se d b eca u se t h e ﬁ rs t t w o l e ve ls a re n early a lw ays s u ﬃ cie n t f o r m akin g a n i d en ﬁca on o r d ete rm in in g a n e xc lu sio n. T a b le 7 .1 : F in ge rp rin t p a ern l e ve ls L e ve l P a ern c a te go ry 1 A rc h , l o op, o r w ho rl 2 M in u ae ( s u ch a s d o t, b if u rc a on, a n d r id ge e n din g) 3 P o re a n d r id ge f e atu re s A n e xa m in er m ay r e ach t h re e p o ssib le c o nclu sio ns f o llo w in g a c o m paris o n: e xc lu sio n , i n co n clu siv e , o r i d en ﬁca on . E xclu sio n m ean s t h at t h e q ues oned p rin t d o es n o t m atc h t h e k n ow n p rin t a n d t h ere fo re t h e p ers o n t o w hic h t h e k n ow n p rin t b elo ngs i s e xc lu ded . I n co nclu siv e m ean s t h e e xa m in er c a n n eit h er m ake t h e i d en ﬁca on n o r e xc lu de t h e p ers o n. T h ere i s n ’t e n o ugh i n fo rm a on i n t h e q ues oned p rin t. I d en ﬁca on m ean s t h at t h is q ues oned p rin t i s a rib uta b le t o t h e p ers o n w ho f u rn is h ed t h e k n ow n. D u es o f a L a te n t P rin t E xa m in er I n r e ce n t y e ars , t h ere h ave b een q ues ons a s t o w heth er t h ere i s a s u ﬃ cie n t s c ie n ﬁc u nderp in nin g t o ﬁ nge rp rin t c o m paris o ns t o w arra n t t h e i d en ﬁca on c o nclu sio n ( N a onal R ese arc h C ouncil, 2 009; K o eh le r & S a ks, 2 010). H ow d o w e k n ow ﬁ nge rp rin ts a re i n div id ual? T h e s ta n dard a n sw er i s t h at h undre d s o f t h o usa n ds o f p rin ts h ave b een c o m pare d , a n d n o t w o h ave b een f o und t h at a re a lik e . T h is s ta n dard a n sw er i s c o rre ct, b ut o ne p ers o n d id n o t a n aly ze a ll o f t h ese p air w is e c o m paris o ns. T h at i s , t h e s u m t o ta l o f a ll t h e p air w is e c o m paris o ns w as d o ne b y m an y d iﬀ ere n t p eo ple a t d iﬀ ere n t m es. F u rth erm ore , a n e xa m in er d o esn ’t c o m pare a q ues oned p rin t w it h m illio ns o f k n ow ns; t h e q ues oned p rin t i s c o m pare d w it h o nly a f e w . W it h A FIS s y ste m s, t h e m ul ple p air w is e c o m paris o n a rg u m en t i s m uch m ore s u ppo rta b le . I f a q ues oned p rin t i s s e arc h ed w it h in I A FIS a n d f o und, t h at q ues oned p rin t w as c o m pare d w it h a ll t h e p rin ts i n t h e d ata b ase . T o d ate , n o o ne h as f o und t w o o r t h re e m atc h es— only o ne ( o r n o ne, i f t h e p rin t i s n ’t i n I A FIS ). T h e f a ct t h at s o m an y s e arc h es h ave b een c o m ple te d l e n ds c o nsid era b le s u ppo rt t o t h e i n div id ualit y i d ea. T h in k A bo ut I t F ro m e ve ry th in g y o u h ave l e arn ed s o f a r, d o y o u t h in k t h ere a re t w o p eo ple w ho h ave e xa ctly t h e s a m e t e n ﬁ nge rp rin ts ? W hat a b o ut t w o p eo ple w ho h ave o ne ﬁ nge rp rin t i d en ca l t o o ne o f t h e o th er p ers o n’s ? W hat a b o ut t w o p eo ple w ho h ave a p ar al o f o ne ﬁ nge rp rin t i d en ca l t o t h e p ar al ﬁ nge rp rin t o f t h e o th er p ers o n? N eve rth ele ss, a h ig h p ro ﬁ le c a se f r o m 2 004 h as c a u se d t h e t h in kin g t o b e r e co nsid ere d . T h e r e al q ues on i s n o t s o m uch w heth er c o m ple te ﬁ nge rp rin ts a re d uplic a te d t o t h e e xte n t t h at a t ra in ed e xa m in er c a n ’t t e ll t h em a p art, b ut w heth er t h ere i s a c h an ce t o g e t a p ar al d uplic a te .

T h at i s , p re se n te d w it h a n i n co m ple te q ues oned i m pre ssio n, c o uld t h ere b e t w o p rin ts o ut i n t h e w orld t h at c o uld b e i n te rp re te d t o " m atc h "? S e e w hat y o u t h in k a er r e ad in g t h e c a se o f U nit e d S ta te s v . B ra ndon M ayﬁ eld . C ase I llu stra on: U nit e d S ta te s v . B ra ndon M ayﬁ eld B ra n do n M ayﬁ eld w as a M uslim a orn ey p ra c cin g i n O re go n. H e w as a U .S . c i ze n a n d A rm y v e te ra n . H e c o nve rte d t o I s la m a er m ee ng a n d m arr y in g h is E gyp an ‐b o rn w if e . O n M arc h 1 1, 2 004, a s e rie s o f c o ord in ate d b o m bin gs d id e xte n siv e d am age t o S p ain ’s c o m mute r t ra in s y ste m i n M ad rid , k illin g 1 91 p eo ple a n d w oundin g a ro und 1 ,8 00 o th ers . T h e a ack w as p erp etra te d b y a l o ca l t e rro ris t c e ll, i n sp ir e d b y b ut n o t d ir e ctly c o nnecte d t o A l Q aid a. I n t h e s u bse q uen t i n ve s ga on, a b ag c o nta in in g d eto na ng d evic e s w as r e co ve re d b y t h e S p an is h p o lic e a n d l a te n t ﬁ nge rp rin ts w ere f o und. T h ese w ere s h are d w it h o th er c o untr ie s’ l a w e n fo rc e m en t a ge n cie s t o h elp w it h t h e c a se . T h e F B I ﬁ nge rp rin t u nit r a n a n A FIS s e arc h a n d g e n era te d a n um ber o f p o te n al m atc h es. M ayﬁ eld ’s p rin ts w ere a m ong t h em . P o ssib ly b eca u se h e w as M uslim a n d h ad p ro vid ed l e ga l a ssis ta n ce t o s o m e M uslim c lie n ts , h e b eca m e a p rin cip al s u sp ect. F B I ﬁ nge rp rin t e xp erts w ork in g o n t h e c a se c a m e t o t h e c o nclu sio n t h at t h e e vid en ary l a te n ts m atc h ed M ayﬁ eld , a n d s e ve ra l o f t h em — all h ig h ly e xp erie n ce d a n d s e aso ned e xa m in ers — agre ed o n t h is c o nclu sio n. T h e F B I c o nducte d a d eta ile d i n ve s ga on o f M ayﬁ eld , a n d e ve n tu ally a rre ste d h im . T h ere w ere d is c u ssio ns a n d a t l e ast o ne m ee ng b etw een F B I e xa m in ers a n d S p an is h ﬁ nge rp rin t e xa m in ers , i n w hic h t h e l a er t o ld t h e F B I t h at t h e p rin ts d id n o t m atc h M ayﬁ eld . H ow eve r, t h e F B I c o n nued t h e i n ve s ga on u n l i t b eca m e c le ar t h at t h e F B I w as i n co rre ct o n t h is i d en ﬁca on. I t w as f o und t h at t h e p rin ts b elo nge d t o a n A lg e ria n n a onal n am ed O uhnan e D ao ud. T h e F B I r e le ase d a n d a p o lo giz e d t o M r. M ayﬁ eld a n d t h e g o ve rn m en t s e le d a s u it h e ﬁ le d a ga in st i t f o r $ 2 m illio n. T h ere w as a p ublic d is c u ssio n i n vo lv in g f e d era l o ve rre ach i n t h e i n ve s ga on, a sid e f r o m t h e ﬁ nge rp rin t i s su e. M r. M ayﬁ eld s u ed t h e g o ve rn m en t s e ekin g t o o ve rtu rn p arts o f t h e P A TR IO T A ct ( N ew Y o rk T im es , 2 006).

R eﬂ ect O n I t A naly zin g p alm p rin ts i s n o t a s c o m mon a s ﬁ nge rp rin ts , a s ﬁ nge rp rin ts a re m ore p re va le n t. D o y o u t h in k ﬁ nge rp rin ts s h ow m ore d iﬀ ere n ce s b etw een i n div id uals t h an p alm p rin ts d o ? O rlin W agner/ A sso cia te d P re ss R eﬂ ect O n I t W hat d o y o u t h in k a bou t t h e m is id en ﬁca on o f t h is c a se ? W as i t b ia s, i n co rre ct e xa m in a on o f t h e ﬁ ngerp rin ts , o r a c o m bin a on o f b oth t h at l e d t o t h e w ro n g a rre st? W hat d o y o u t h in k c o u ld h ave p re ve n te d t h is ? I t h as b een s u gge ste d b y ﬁ nge rp rin t c ri cs t h at m is id en ﬁca on o ccu rre d i n t h is c a se b eca u se o f e xa m in er b ia s. T h ey s ta te t h at F B I e xp erts k n ew a ll a b o ut t h e c a se , a n d t h o ugh t i t s h o uld b e a m atc h , a n d t h at k n ow le d ge e n ded u p d eep ly p re ju dic in g t h em . I n a n y e ve n t, i t d o es s h ow t h at i d en ﬁca on e rro rs c a n h ap pen . Y o u m ay b e t h in kin g a s y o u r e ad t h is s e c on a n d t h is c a se e xa m ple , w hy i s n ’t t h ere a m in im um n um ber o f p o in ts t o d eﬁ ne a m atc h ? I t s o unds e asy , b ut i t i s n ’t . T h ere w as s u ch a c rit e rio n i n t h e U nit e d K in gd o m f o r q uit e s o m e m e. B ut, i t t u rn ed o ut t h at n o n‐m atc h in g ﬁ nge rp rin ts c o uld h ave t h e m in im um r e q uir e d n um ber o f p o in ts . I t i s a ls o t h e c a se t h at a n e xa m in er m ay n o t a lw ays h ave t h e m in im um n um ber, b ut i s c o nvin ce d t h e p rin ts m atc h . F o r t h ese r e aso ns, t h e I A I, t h e p ro fe ssio nal o rg a n iz a on t h at m ake s i n te rn a onal c o nse n su s s ta te m en ts a b o ut t h ese m a ers , h as l o ng t a ke n t h e p o si on t h at t h ere s h o uld n o t b e a s p eciﬁ ed n um ber o f m atc h in g m in u ae o r p o in ts t o d ecla re a m atc h . A s n o te d , t h e I A I i s c o n nuin g t o e xa m in e i t s p rin cip le s r e ga rd in g ﬁ nge rp rin t i d en ﬁca on ( P o ls k i e t a l. , 2 011). A no th er w ay o f l o okin g a t e xa m in er a ccu ra cy i s t h ro ugh p ro ﬁ cie n cy t e sts . E xa m in ers a re s u bje cte d t o t h ese p ro ﬁ cie n cy t e sts f o r c e r ﬁca on a n d r e ce r ﬁca on. S o m e a ge n cie s a n d a ccre d it e d f o re n sic l a b s a ls o p ar cip ate i n p ro ﬁ cie n cy t e s ng f o r t h eir e xa m in ers . A t m es, t h e t e sts c a n b e d o ne f o r r e se arc h p urp o se s a s w ell. I n p ro ﬁ cie n cy t e sts , e xa m in ers a re g iv e n s e ts o f q ues oned p rin ts o r p ar als a lo ng w it h k n ow n p rin ts , a n d t o ld t o c o m ple te p air w is e c o m paris o ns a n d f o rm c o nclu sio ns. T h e v a st m ajo rit y o f t e sts a n d s tu die s o f t h is t y p e s h ow t h at t h e e xa m in ers g e t t h e r ig h t a n sw ers . O ne s tu dy i n vo lv in g t h e ﬁ nge rp rin ts o f i d en ca l t w in s r e su lt e d i n a f e w m is id en ﬁca ons ( G rie ve , 1 996). I d en ca l t w in ﬁ nge rp rin ts a re d is ngu is h ab le , b ut t h ey c a n b e v e ry s im ila r. A naly sis o f O th er F ric on R id ge I m pre ssio ns F ric on r id ge s k in i m pre ssio ns, s u ch a s p alm p rin ts a n d f o otp rin ts , a re c o m pare d i n t h e s a m e w ay a s ﬁ nge rp rin ts a re c o m pare d . T o c la rif y , o en m es p eo ple r e fe r t o " fo otw ear i m pre ssio ns" a s f o otp rin ts , b ut t h is i s i n co rre ct. F o otp rin ts a re m ad e b y b are f e et. T h e m ain d iﬀ ere n ce b etw een t h ese t y p es o f f r ic on r id ge s k in i m pre ssio ns a n d ﬁ nge rp rin ts i s t h at ﬁ le s o f p alm o r f o otp rin ts a re n o t m ain ta in ed b eca u se t h ese i m pre ssio ns a re l e ss f r e q uen tly e n co unte re d t h an ﬁ nge rp rin ts . G en era lly , i n ve s ga to rs m ust d eve lo p o ne o r m ore s u sp ects , t h en a rra n ge t o c o lle ct i n ke d p alm o r f o ot i m pre ssio ns a s k n ow ns f o r c o m paris o n. T h e m eth o ds u se d f o r c o m paris o n a n d t h e c rit e ria f o r c o nclu sio ns a re t h e s a m e a s f o r ﬁ nge rp rin ts . C h. 7 C onclu sio n P a ern s a re a n i m po rta n t c la ss o f e vid en ce . I d en ﬁca on p a ern s r e fe r t o t h e m en ta l i m age s u se d t o c la ssif y o bje cts i n t h e e n vir o nm en t. I n div id ualiz a on p a ern s c a n b e p hysic a l p a ern s o r i m pre ssio ns. T h e m ost c o m monly s e en i m pre ssio ns a re f o otw ear a n d re t ra ck s. R eco nstr u c on p a ern s h elp i n ve s ga to rs f o rm t h eo rie s a b o ut e ve n ts t h at t o ok p la ce i n t h e p ast, b ase d o n t h e p hysic a l e vid en ce r e co rd . P a ern e vid en ce i s c o lle cte d b y p ho to gra p hy, l i in g, a n d c a s ng, a s a p pro pria te . I t i s a n aly ze d b y c o m parin g a q ues oned i m pre ssio n w it h a k n ow n i m pre ssio n o r o bje ct. A p ro per c o m paris o n r e q uir e s t h at o nly l ik e i m pre ssio ns b e c o m pare d ( p o si ve s, n ega ve s, l e , r ig h t, e tc .) . S o m e p a ern e vid en ce c a n s o m e m es b e i n div id ualiz e d . F in ge rp rin ts a re a n i m po rta n t c a te go ry o f e vid en ce , a n d h ave a l e n gth y h is to ry o f u se a s a m ean s o f p ers o nal i d en ﬁca on. A uto m ate d ﬁ nge rp rin t i d en ﬁca on s y ste m s h ave e n ab le d t h e s to ra ge a n d s e arc h o f s in gle ﬁ nge rp rin ts , a n d r e n dere d t e n ‐p rin t c a rd s a n d c la ssiﬁ ca on s y ste m s o bso le te . A t s c e n es, v is ib le , p la s c, a n d l a te n t p rin ts c a n b e f o und. L a te n t p rin ts r e q uir e s o m e v is u aliz a on t e ch niq ues t o m ake t h e r id ge d eta il s u it a b le f o r c o m paris o n. T h ere a re p hysic a l, c h em ic a l, a n d i n str u m en ta l m eth o ds f o r d eve lo pin g l a te n t p rin ts . Q ues oned ﬁ nge rp rin ts a re c o m pare d w it h k n ow n p rin ts , a n d e xa m in ers c a n o en i n div id ualiz e t h e p rin t t o a p ers o n, o r e xc lu de a p ers o n a s t h e s o urc e . S o m e m es, p rin ts a re n o t s u it a b le f o r c o m paris o n, o r t h ere i s i n su ﬃ cie n t d eta il t o r e ach a c o nclu sio n. T h ere h as b een d is c u ssio n a b o ut t h e s c ie n ﬁc b asis f o r ﬁ nge rp rin t i n div id ualit y , a n d w heth er i n div id ualiz a on i s j u s ﬁed i n ﬁ nge rp rin t c o m paris o n, p ar cu la rly w it h q ues oned p ar al p rin ts . P alm p rin ts a n d f o otp rin ts a re s o m e m es e n co unte re d a t s c e n es, a n d t h ey m ay b e c o m pare d t o k n ow ns i n t h e s a m e w ay a s ﬁ nge rp rin ts . C h. 7 L e arn in g R eso urc e s K ey I d eas T h ere a re p a ern s f o r i d en ﬁca on, f o r i n div id ualiz a on, a n d f o r r e co nstr u c on. I m po rta n t p a ern s f o r i n div id ualiz a on i n clu de p hysic a l m atc h es, a s w ell a s i m prin t a n d i n den ta on m ark in gs, o f w hic h f o otw ear a n d re i m pre ssio ns m ay b e t h e m ost c o m mon. F in ge rp rin ts a re a n i m po rta n t c la ss o f p hysic a l e vid en ce a n d a n e xa m ple o f a b io m etr ic i d en ﬁer. A FIS s y ste m s e n ab le r a p id s e arc h a n d r e tr ie va l o f s in gle ﬁ nge rp rin ts . L a te n t ﬁ nge rp rin ts r e q uir e v is u aliz a on o r p ro ce ssin g s te p s i n o rd er t o b e s u it a b le f o r c o m paris o n. T h ere i s a m eth o d f o r ﬁ nge rp rin t ( a n d o th er f r ic on r id ge p rin t) c o m paris o ns c a lle d A CE‐V , w hic h d esc rib es t h e s te p s a n e xa m in er f o llo w s t o c o m pare q ues oned a n d k n ow n p rin ts . F in ge rp rin ts a re i n div id ual. W it h v e ry r a re e xc e p ons, i d en ﬁca ons o r e xc lu sio ns c a n b e m ad e f o llo w in g a c o m paris o n b y a q ualiﬁ ed e xa m in er. F o ot a n d p alm p rin ts a re c o m pare d i n t h e s a m e m an ner a s ﬁ nge rp rin ts . C ri ca l T h in kin g Q ues ons 1 . I n a c rim in al a g gra va te d a ssa u lt c a se , t h e a ccu se d r ip ped o ﬀ t h e v ic m ’s d re ss, a n d i n t h e p ro ce ss, a p ie ce b eca m e c o m ple te ly s e p ara te d a n d g o t s tu ck o n t h e b ack o f t h e p erp etra to r’s s h ir t. T h e p o lic e l a te r r e co ve re d t h e s h ir t, w hic h s ll h ad t h e f r a gm en t o f d re ss o n i t . I m agin e t h at y o u a re t h e l a b e xa m in er, c o m parin g t h e f r a gm en t t o t h e d re ss. T h is i s a s u m mer‐w eig h t, l ig h t m ate ria l w it h a d is nc ve , d eco ra ve p a ern o n i t . T h e f r a gm en t l in es u p a lm ost p erfe ctly w it h a m is sin g a re a o n t h e v ic m ’s d re ss. C olo r a n d p a ern a re t h e s a m e. T h re ad c o unt i s t h e s a m e. I t d eﬁ nit e ly c o uld b e t h e m is sin g p ie ce . H ow w ould y o u t e s fy t o t h is ﬁ ndin g? 2 . I n a c rim in al c a se , a s u sp ect i s t h o ugh t t o h ave k ic ke d i n a m eta l d o or w hile w earin g a s n eake r. T h e p o lic e s u cce ssfu lly u se a n e le ctro sta c d ust l i er t o l i a g o od d ust p rin t o f t h e s n eake r f r o m t h e d o or. T h ey a ls o h ave a s u sp ect, a n d t h e s n eake r t h ey t h in k p ro bab ly m ad e t h e m ark . H ow w ould y o u, a s t h e e xa m in er, m ake t h e " k n ow n" s n eake r i m pre ssio n t o c o m pare w it h t h e d ust p rin t? 3 . A g o ve rn m en t a ge n cy i s w illin g t o f u nd a s tu dy t o e sta b lis h t h at ﬁ nge rp rin ts a re r e ally i n div id ual. H ow w ould y o u d esig n t h is s tu dy? D esc rib e t h e s tu dy d esig n , t h e r e su lt s t h at m ig h t b e e xp ecte d , a n d t h e c o nclu sio ns t h at c o uld b e d ra w n f r o m t h em . 4 . I n a h o m ic id e c a se , t h e p o lic e ﬁ nd a g o od b lo ody f o otp rin t o n a b ath ro om ﬂ oor le . T h ey t h in k t h e f o otp rin t b elo ngs t o t h e p erp etra to r. T h ey h ave a s u sp ect i n c u sto dy, b ut t h ey c a n no t p ro ve h e w as a t t h e s c e n e a t t h e m e o f t h e c rim e. Y o u a re t h e e xa m in er a n d a re g iv e n t h e le w it h t h e q ues oned f o otp rin t o n i t . H ow w ould y o u t e ll t h e p o lic e t o c o lle ct t h e k n ow n f o otp rin ts f r o m t h e d ece d en t a n d f r o m t h e s u sp ect? D o y o u t h in k t h e p o lic e n eed a s e arc h w arra n t t o c o lle ct t h e k n ow n f o otp rin t f r o m t h e s u sp ect? 5 . Y o u a re t h e ﬁ nge rp rin t e xp ert w it n ess i n a c rim in al t r ia l. A n o bje ct f r o m t h e c rim e s c e n e h ad a g o od l a te n t p rin t o n i t , a n d y o u w ere a b le t o m atc h t h e l a te n t t o t h e k n ow n p rin t f r o m o ne o f t h e d efe n dan t’s ﬁ nge rs . Y o u h ave t e s ﬁed t h at t h e l a te n t ﬁ nge rp rin t c a m e f r o m t h e d efe n dan t. T h e d efe n se l a w ye r n ow s a ys t o y o u t h e f o llo w in g: " T h e p o lic e h ad a t e n ‐p rin t c a rd o n ﬁ le c o nta in in g t h e d efe n dan t’s ﬁ nge rp rin ts . A t t h e m e t h e p o lic e a rre ste d t h e d efe n dan t, t h ey h ad v e ry l i le e vid en ce t h at h e w as a ctu ally a t t h e s c e n e, b ut t h ey w ere c o nvin ce d h e w as t h eir g u y. S u ppo se t h ey t o ok s o m e l i in g t a p e a n d c a re fu lly l i ed o ﬀ o ne o f t h e p rin ts f r o m t h e t e n ‐p rin t c a rd , t h en u se d t h at t a p e t o p la ce t h e ‘ la te n t p rin t’ o n t h e o bje ct f r o m t h e s c e n e t h at w as s u bm i ed t o y o u f o r e xa m in a on. D o y o u c o nce d e t h at t h is s c e n ario i s p o ssib le ? I f s o , w ould y o u a gre e t h at t h e l a te n t m atc h t o t h e d efe n dan t d o es n o t t h en p ro ve t h at h e w as a ctu ally a t t h e s c e n e?" K ey T e rm s C lic k o n e a ch k e y t e rm t o s e e t h e d eﬁ ni on . a ccid en ta l ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A n i n div id ual c h ara cte ris c i n a n i t e m o f f o otw ear, a re , o r o th er o bje ct t h at o ccu rs a s t h e r e su lt o f w ear a n d e xp o su re , a n d t h at c a n b e d ete cte d i n a n i m prin t o r i n den ta on o f t h e i t e m . A naly sis , C o m paris o n, E va lu a on, a n d V eric a on ( A CE‐V ) ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) T h e p ro ce ss f o llo w ed b y ﬁ nge rp rin t e xa m in ers i n t h eir c o m paris o ns o f k n ow n a n d q ues oned ﬁ nge rp rin ts , a s w ell a s f o ot o r p alm p rin ts . b io m etr ic ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) L it e ra lly , a n y b io lo gic a l f e atu re t h at m ig h t b e u se d t o d is ngu is h p eo ple . F in ge rp rin ts a re a n e xa m ple o f a b io m etr ic i d en ﬁer. b it e m ark ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A m ark m ad e i n a s o r e ce iv in g s u rfa ce b y h um an t e eth . H um an t e eth , a n d t h us t h e m ark p a ern s t h ey m ake , a re b elie ve d t o h ave i n div id ual c h ara cte ris cs. d ir e ct p hysic a l m atc h ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A p hysic a l m atc h o f p ie ce s o f a r a n do m ly f r a ctu re d s o lid m ate ria l, s u ch a s g la ss o r p la s c, i n t h e m an ner o f a j ig sa w ﬁ t. e xclu sio n ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A c o nclu sio n b y a n e xa m in er t h at a q ues oned s p ecim en c a n no t h ave o rig in ate d f r o m a k n ow n s p ecim en w it h w hic h i t h as b een c o m pare d . i d en ﬁca on ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) I n p a ern e vid en ce c o m paris o ns, t h is t e rm m ean s i n div id ualiz a on, a c o nclu sio n t h at t h e q ues oned s p ecim en o rig in ate d f r o m t h e k n ow n w it h w hic h i t w as c o m pare d . i m pre ssio n ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A ny m ark m ad e b y a n o bje ct i m pre ssin g i t s s h ap e a n d f o rm i n to o r o nto a n o th er o bje ct o r s u rfa ce . I m pre ssio ns c a n b e i m prin ts o r i n den ta ons. i m prin t ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A n e ﬀ ec ve ly " tw o‐d im en sio nal" i m pre ssio n. i n co nclu siv e ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) I n p a ern e vid en ce c o m paris o ns, t h is c o nclu sio n m ean s t h at t h ere i s n o t s u ﬃ cie n t i n fo rm a on t o d ra w a d eﬁ nit e c o nclu sio n; t h at i s , w e c a n no t s a y f o r s u re w heth er t h e q ues oned i s e xc lu ded o r t h ere i s a n i d en ﬁca on.

i n den ta on ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A t h re e‐d im en sio nal i m pre ssio n. i n dir e ct p hysic a l m atc h ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A p hysic a l m atc h o f p ie ce s o f a n o n‐s o lid i t e m o r o bje ct t h at h as b een c u t o r t o rn , o r o f a s o lid o bje ct t h at f r a ctu re s i n s u ch a w ay t h at t h e p ie ce s c a n no t b e d ir e ctly r e alig n ed . l a te n t ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) L it e ra lly , " h id den ." A l a te n t ﬁ nge rp rin t i s o ne t h at r e q uir e s p ro ce ssin g o r d eve lo pm en t i n o rd er t o b e v is ib le a n d s u it a b le f o r c o m paris o n. m in u ae ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) ( s in gu la r: m in u a) T h e i n div id ualiz in g c h ara cte ris cs o f a ﬁ nge rp rin t p a ern . P rim arily , e xa m in ers u se d o ts , b if u rc a ons, a n d e n din g r id ge s. n in hyd rin ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A c h em ic a l t h at r e acts w it h a m in o a cid s t o f o rm a v is ib le , v io le t‐ c o lo re d p ro duct. I t i s u se d t o v is u aliz e l a te n t ﬁ nge rp rin ts . p ate n t ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) L it e ra lly , " v is ib le " o r " o bvio us." A p ate n t ﬁ nge rp rin t i s v is ib le . p la s c ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A n i n den ta on ﬁ nge rp rin t t h at h as b een i m pre sse d i n to a s o r e ce iv in g s u rfa ce s o a s t o h ave d ep th . s tr ia on ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A s lid in g t o ol m ark , r e su l ng f r o m o ne s u rfa ce s lid in g o n a n o th er a n d t h us c re a ng a m ark . s u per g lu e ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A c o m merc ia l a d hesiv e , c h em ic a lly a c y a n o acry la te e ste r, w hic h c a n b e u se d t o d eve lo p l a te n t ﬁ nge rp rin ts b y f u m in g t h e g lu e o nto t h e p rin t r e sid ue. t e n ‐p rin t c a rd ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) F o rm erly , ﬁ nge rp rin ts f r o m i n div id uals w ere c o lle cte d o n c a rd s f o rm a ed t o h o ld i n fo rm a on a b o ut t h e p ers o n p lu s i n ke d ﬁ nge rp rin ts f r o m a ll t e n ﬁ nge rs . T h e t e n ‐p rin t c a rd w as t h e b asis o f c la ssiﬁ ca on s y ste m s, a n d t h e c a rd s w ere k e p t i n p hysic a l ﬁ le s. v is ib le ( h p:/ /c o nte n t.t h uze le arn in g.c o m /b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er/ b o oks/A U CR J3 11.1 3.1 /se c ons/ fr o nt_ m a er# ) A ble t o b e s e en . A v is ib le p rin t c a n b e s e en w it h n o d eve lo pm en t o r p ro ce ssin g. W eb R eso urc e s W eb sit e f o r t h e S cie n ﬁc W ork in g G ro up o n F ric on R id ge A naly sis , S tu dy a n d T e ch no lo gy ( S W GFA ST ): h p:/ /w ww.s w gfa st.o rg / ( h p:/ /w ww.s w gfa st.o rg /) S m it h so nia n C han nel v id eo o n w here ﬁ nge rp rin ts c a m e f r o m : h p:/ /w ww.s m it h so nia n ch an nel. c o m /sit e /sn /sh ow .d o ?se rie s= 8 26#w here ‐d o ‐ﬁ nge rp rin ts ‐c o m e‐f r o m ( h p:/ /w ww.s m it h so nia n ch an nel. c o m /sit e /sn /sh ow .d o ?se rie s= 8 26#w here ‐d o ‐ﬁ nge rp rin ts ‐c o m e‐f r o m ) S m it h so nia n C han nel v id eo c lip o n t h e u se o f l a se rs t o v is u aliz e ﬁ nge rp rin ts : h p:/ /w ww.s m it h so nia n ch an nel. c o m /sit e /sn /sh ow .d o ?e p is o de=1 41423 ( h p:/ /w ww.s m it h so nia n ch an nel. c o m /sit e /sn /sh ow .d o ?e p is o de=1 41423) S m it h so nia n C han nel v id eo c lip o n ﬁ nge rp rin ts : h p:/ /w ww.s m it h so nia n ch an nel. c o m /sit e /sn /v id eo /p la ye r/ sc ie n ce ‐a n d‐n atu re /re la te d /w here ‐d o ‐ﬁ nge rp rin ts ‐c o m e‐f r o m /1 628666392001/ ( h p:/ /w ww.s m it h so nia n ch an nel. c o m /sit e /sn /v id eo /p la ye r/ sc ie n ce ‐a n d‐ n atu re /re la te d /w here ‐d o ‐ﬁ nge rp rin ts ‐c o m e‐f r o m /1 628666392001/) F e d era l S p ecia l R ep o rt o n t h e c a se o f B ra n do n M ayﬁ eld : h p:/ /w ww.ju s ce .g o v/o ig /sp ecia l/ s0 601/P D F_ lis t.h tm ( h p:/ /w ww.ju s ce .g o v/o ig /sp ecia l/ s0 601/P D F_ lis t.h tm )