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6 Death Investigation

Phil Noble/AFP/Newscom

LEARNING OBJECTIVES

After studying this chapter, you should be able to:

• Describe the role of the forensic pathologist

• Distinguish cause and manner of death

• Describe common causes of death

• Describe the external, internal, and toxicology phases of an autopsy

• List various categories associated with the manner of death

• Describe chemical and physical changes helpful for estimating time of death

• Discuss the role of the forensic anthropologist in death investigation

• Describe the role of the forensic entomologist in death investigation

HAROLD SHIPMAN, DR. DEATH

Kathleen Grundy’s sudden death in 1998 was shocking news to her daughter, Angela Woodruff. Mrs. Grundy, an 81-year-old

widow, was believed to be in good health when her physician, Dr. Harold Shipman, visited her a few hours before her

demise. Some hours later, when friends came to her home to check on her whereabouts, they found Mrs. Grundy lying on a

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sofa fully dressed and dead.

Dr. Shipman pronounced her dead and informed her daughter that an autopsy was not necessary. A few days later, Mrs.

Woodruff was surprised to learn that a will had surfaced leaving all of Mrs. Grundy’s money to Dr. Shipman. The will was

immediately recognized as a forgery and led to the exhumation of Mrs. Grundy’s body. A toxi-cological analysis of the

remains revealed a lethal quantity of morphine.

In retrospect, there was good reason to suspect that Dr. Shipman was capable of foul play. In the 1970s, he was asked to

leave a medical practice because of a drug abuse problem and charges that he obtained drugs by forgery and deception.

However, Dr. Shipman was quickly back to practicing medicine. By 1998, local undertakers became suspicious because of

the number of his patients who were dying. What is more, the patients that had died all were elderly women who were found

sitting in a chair or lying fully clothed on a bed. As police investigated, the horror of Dr. Shipman’s deeds became apparent.

One clinical audit estimated that Dr. Shipman had killed at least 236 of his patients over a twenty-four-year period. Most of

the deaths were attributed to fatal doses of heroin or morphine. Toxicological analysis on seven exhumed bodies clearly

showed significant quantities of morphine. Convicted of murder, Dr. Shipman hanged himself in his jail cell in 2004.

Role of the Forensic Pathologist

Few investigations bring with them the intense focus of community interest and news media coverage as that of a suspicious

death. Generally, forensic pathologists associated with the medical examiners’ or coroner’s office are responsible for

determining the cause of an undetermined or unexpected death. These officers will coordinate their response with that of law

enforcement in the ensuing investigation. The titles coroner and medical examiner are often used interchangeably, but there

are significant differences in their job descriptions. In the United States, there’s a mix of state medical examiner systems,

county medical examiner offices, and county coroner systems. The coroner is an elected official and may or may not possess

a medical degree. (The term coroner dates back hundreds of years to the rule of King Henry II of England, who created the

office of the coroner to collect money and personal possessions from people who had died.) The medical examiner, on the

other hand, is almost always an appointed official and is usually a physician who generally is a board-certified forensic

pathologist and is responsible for certifying the manner and the cause of a death.

forensic pathologists

Investigative personnel, typically medical examiners or coroners, who investigate the cause, manner and time of death of a

victim in a crime. A physician who has been trained to conduct autopsies.

The tasks of examining the death for the cause and manner of death and recording the results in a death certificate are the

responsibilities of both offices. However, although both the coroner’s office and the medical examiner’s office are charged

with investigating suspicious deaths, only the pathologist is trained to perform an autopsy. Ideally, the coroner or medical

examiner’s office should be staffed with physicians who are board certified in forensic pathology and should charge them

with determining the cause of death by autopsy. The cause-of-death determination, however, involves not just an autopsy but

also the history of death, witness statements, relevant medical records, and any scene investigation, all of which constitute

the surrounding circumstances of death.

From a practical point of view, it is often not feasible for the forensic pathologist to personally solicit information regarding

the circumstances surrounding a death or to respond in-person to every death scene. Thus, the gathering of vital information

and the scene investigation can be delegated to trained coroner/medical examiner investigators who, when a crime scene is

involved, coordinate their efforts with the those of crime-scene and criminal investigators. The forensic pathologist’s work is

also aided by the skills of specialists including forensic anthropologists, forensic entomologists, and forensic odontologists.

SCENE INVESTIGATION

With regard to any scene investigation, protection of the overall scene and the body are of paramount importance, as is the

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ultimate removal of the body in a medically acceptable manner. The death investigation involves documenting and

photographing the undisturbed scene; collecting relevant physical evidence; attempting to determine time of death, which

must be done in a timely fashion at the scene; and, among other things, ascertaining premortem locations of the body and

whether any postmortem movement of the body occurred. Examples of observations that can be made of the body at the

scene include bruises along the upper lip, which may be evidence of smothering; a black eye limited to the eyelids, which

implies an injury from inside the head; or bleeding from the ear, which implies a basal skull fracture.

A critical phase of the death investigation will be a preliminary reconstruction of events that preceded the onset of death, so

all significant details of the scene must be recorded. Blood spatter and blood flow patterns must be documented. Blood

should be sampled for testing in case some of the blood was cast off by a perpetrator. Any tire marks or shoe prints must be

documented. Fingerprints must be processed and collected. Of particular importance is the search for any evidence discarded,

dropped, or cast off by a perpetrator. When a weapon is involved, there must be a concerted effort to locate and recover the

suspect weapon. In the case of firearm deaths, fired bullets or casings must be found and their locations documented. In such

firearm deaths, before the body is moved or clothing is removed, blood spatter directionality and trace evidence (such as

hairs) on the hands must be documented. Paper bags then should be placed over the hands and secured around the wrist or

arm (paper prevents moisture condensation) to preserve any additional evidence.

Photographs must always be taken before the scene is altered in any way (except from life-saving efforts). This includes

moving the body or anything on the body, such as clothing or jewelry. A particularly violent scene can carry with it a large

amount of blood and disorder. Blood may be found at different locations throughout the scene. This could prove to be

important in shaping the events that led to the final outcome; it may be possible to determine the initial location of the injury,

as well as victim and assailant movements throughout the course of events. Initially it may be difficult to properly infer the

source of the wounds and the order in which they were received at the scene. Photographs then will play a very large role

when reconstructing the events later. As always, photographs should be taken with a scale, always first overall, then at

medium range, then close up. The photographer must also be careful not to get caught up in capturing the injuries

exclusively. Negative findings can also be significant. This means photographs should also be taken of areas on the body

where injuries are not apparent.

Protection of the body and the overall scene is of paramount importance, as is the ultimate removal of the body in a

medically acceptable manner. Often the initial phase of the investigation will focus on determining the identity of the

deceased, often called the decedent . Although this task may be relatively simple to accomplish through a visual examination,

complications can arise. Body decomposition and the existence of extensive trauma can complicate the identification. This

may necessitate the application of more sophisticated technology, such as DNA, fingerprinting, dental examination, and

facial reconstruction.

Quick Review

• Forensic pathologists associated with the medical examiners’ or coroner’s office are responsible for determining the

cause of an undetermined or unexpected death.

• Although both the coroner’s office and the medical examiner’s office are charged with investigating suspicious

deaths, only the pathologist is trained to perform an autopsy. The tasks of examining a body for the cause and manner

of death and recording the results in the death certificate are the responsibilities of both offices.

• Protection of the body and the overall scene is of paramount importance, as is the ultimate removal of the body in a

medically acceptable manner.

CAUSE OF DEATH

A primary objective of the autopsy is to determine the cause of death. The cause of death is that which initiates the series of

events ending in death. The most important determination in a violent death is the character of the injury that started the

chain of events that resulted in death. However, if the sequence of events leading to death is sufficiently prolonged, then the

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decedent may actually suffer from adverse medical conditions brought about by the initial injury and then die as a result of

those conditions. In that case, it will be up to the forensic pathologist to make the determination that the original injury

inflicted on the victim was the underlying cause of death. Some of the more common causes of death are discussed here.

cause of death

Identifies the injury or disease that led to the chain of events resulting in death.

FIGURE 6-1 Bruising (contusions) on the skin.

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BLUNT FORCE INJURY

A blunt force injury is caused a non-sharpened object such a bat or pipe. A blunt force injury can abrade, or scrape, tissue. If

tissue is crushed by a blunt force to the point of tearing, an open wound, called a laceration, is produced. Lacerations exhibit

abrasions around the open wound, tissue bridging within the open wound, and torn or disturbed tissue beneath the skin

surrounding the open portion of the wound. Blunt force injury can also crush tissue. This will cause bleeding from tiny

ruptured blood vessels within and beneath the skin, known as a contusion, or bruise (see Figure 6-1 ). Much has been written

about determining the age of bruises, but forensic pathologists have become keenly aware that attempting to “age” bruises

based on color and changes in color over time is fraught with difficulty, and contusions must be interpreted with great care

and reserve. Some contusions only become visible externally over time, and frequently, bruises will not be visible externally

but become eminently visible internally within soft tissues (e.g., in the abdomen, and on the back, arms, and legs).

A contusion can sometimes exhibit the pattern of the weapon used. For example, if a person wearing a ring strikes another

person, the ring may imprint its pattern onto the skin. A person who stomps on another may leave the impression of his or

her shoe heel. Over time, however, the bruise will lose its original shape and pattern and undergo color changes. Some

objects will produce a characteristic bruised perimeter and a white center. The outward appearance of the injuries does not

always coincide with the injuries sustained inside the body. This is something the pathologist must keep in mind when

examining blunt force injuries. A single blow to certain parts of the body can cause instantaneous death with little visible

damage. Likewise, a blow to the head can cause a concussion that can be instantly fatal.

SHARP FORCE INJURIES

Sharp force injuries occur from weapons with sharp edges, such as knives or blades. These weapons are capable of cutting or

stabbing. A cut is formed when the weapon produces an injury that is longer than it is deep. In contrast, a stab is deeper than

its length. As shown in Figure 6-2 , the tissue associated with these types of wounds is not crushed or torn but sliced.

A scene that involves a sharp force injury is usually especially bloody and unruly. Blood may be found at different locations

throughout the scene. Again, this information may make it possible to determine the initial location of the injury as well as

where the body was moved throughout the course of events. Particularly important in sharp force cases is to examine the

victim for defensive wounds. A victim’s forearm that exhibits wounds may indicate defense wounds. These occur when the

victim attempts to fight off the attacker or block assaults. Though defense wounds are more typical on the outer forearms,

they can also be evident on the lower extremities if the victim tries to protect him- or herself by kicking. A lack of any

defense wounds can lead a pathologist to conclude that the victim was either unconscious or somehow tied up during the

assault.

ASPHYXIA

Asphyxia encompasses a variety of conditions that involve interference with the intake of oxygen. For example, death at a

fire scene is caused primarily by the extremely toxic gas, carbon monoxide. When carbon monoxide is present, hemoglobin,

the protein in red blood cells that transports oxygen, will bind to the carbon monoxide instead of oxygen. This is carbon

monoxide poisoning, and this deadly complex of hemoglobin and carbon monoxide is known as carboxyhemoglobin. Bound

up with carbon monoxide, the hemoglobin is prevented from transporting oxygen throughout the body, causing asphyxia.

High levels of carbon monoxide in the blood will cause death. Low levels of carbon monoxide can cause a victim to become

disoriented and lose consciousness.

Carbon monoxide will not continue to build up in the body after death. The levels found in a fire victim then can be used to

determine whether the individual was breathing at the time of the fire. The presence of soot is another indicator that the

victim was alive during the fire. These black particles are often seen in the airway of fire victims that inhaled smoke before

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death. During the autopsy, soot can be observed especially in the larynx and trachea and even in the lungs. Sometimes the

victim will actually swallow the soot. In these cases, traces can be found in the esophagus and the lining of the stomach.

The ultimate cause of a death from hanging is typically the cessation of blood flow to or from the brain. Victims of hangings

may show signs of petechiae on the eyelids, along with a swollen and a blue/purplish appearance of the face. Petechiae are

very small and are caused by blood having escaped into the tissues as a result of capillaries bursting (see Figure 6-3 ).

Although petechiae are witnessed in hanging cases, they are more common in strangulation deaths. Typically the hyoid bone

(the bone on which the tongue rests) and thyroid cartilage (located below the hyoid) are not fractured in cases of hanging. A

break of the thyroid cartilage is common, however, in manual strangulation cases.

petechiae

Pinpoint hemorrhaging often observed in the white area of the victim’s eyes; often observed in strangulation cases.

In hangings it is vitally important to document exactly how the victim was initially found and the position of the encircling

noose, as shown in Figure 6-4 . The type of knot used may strongly support the notion that another person was involved in the

hanging. This means that the knot should always be preserved for later examination. Either the noose should be slipped off

the victim’s head intact, or the noose should be cut distant from the knot. Defense wounds are common on strangulation

victims. Often the marks found on the neck of a victim are the victim’s own, made in the attempt to loosen whatever was

constricting his or her neck. Even in cases of hanging by suicide, there can be defensive wounds on the neck.

FIGURE 6-2 A stab wound.

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FIGURE 6-3 Petechial hemorrhages in a victim’s eye.

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FIGURE 6-4 A ligature pattern on a neck with corresponding ligature.

FIGURE 6-5 A contact gunshot wound to the temple of a suicide victim.

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Smothering can occur by various materials that block the mouth, nose, and internal airway. Pillows or a hand can inhibit

breathing. Gags that are used to silence a victim can be sucked into the airway and block oxygen flow. Typically a death by

smothering is homicidal in nature. Accidental smothering usually occurs only in infants or in cases where a victim is trapped

under an obstruction.

FIGURE 6-6 Powder residue on the hand of a suicide victim.

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GUNSHOT WOUNDS

When evaluating a gunshot wound, the estimated range of fire is one of the most important characteristics to analyze ( Figure

6-5 ). The appearance of the wound can be of help in estimating whether the firearm used to inflict the wound was discharged

while in contact with the victim’s body or from a distance of only inches to many feet away. The investigator will compare

powder residue distribution around the wound to test fires collected from the inflicting firearm to make this estimate.

Obviously if the firearm was fired at a distance of several feet, suicide is a highly unlikely cause of death because the wound

could not have been self-inflicted. Gunpowder residue on the victim’s hand, as shown in Figure 6-6 , is a possible indicator of

suicide, but this is not always the case. Evidence of contact shots, that is, shots fired with the gun held against the body of the

victim, typically indicates that the death was not an accident. The autopsy must include a determination of the path or

“wound track” of the projectile. The wound track is determined by observing the wound from the outside of the body,

following the track of the projectile through the body, and documenting its terminus. The pathologist will recover any and all

projectiles from the body, carefully protecting its forensic markings. The autopsy of gunshot victims should include several

facts in addition to the general autopsy facts: Scene investigation and the results of toxicological and serological analyses are

important. All findings regarding the bullet wounds should be noted, as well as descriptions of the clothing. The police report

with a thorough description of the scene is also important.

A gunshot wound may not necessarily explain why a victim died. A person who sustains a gunshot wound can bleed to death

in a matter of minutes or up to several hours. Infection can also be a contributory cause of death, especially in cases where

the victim was shot in the abdomen: He or she might live several days but eventually succumb to infection. In cases where

the victim was shot in the head but survives in a comatose state, pneumonia often develops. These intervening factors are

considered contributory causes of death, but the gunshot wound is still considered the underlying cause of death.

SUBSTANCE ABUSE

Drug abuse continues to be an enormous problem in the United States. Drug enforcement is a multibillion-dollar industry.

Many of the abused drugs in the country are illegal, but not all are. Deaths as a result of substance abuse are common cases

that a forensic pathologist must face. Because drug abuse is so common, the forensic pathologist will routinely test for the

presence of drugs in nearly all investigations, and routine tests are available for many commonly abused drugs. As

technology has improved, many drugs can be detected at very low levels. These factors have helped considerably in making

substance abuse testing easier and less expensive.

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Drug abuse can directly cause death, or it can cause complications that can serve as a contributing factor to death. An abuser

can misuse a drug or a number of drugs for years, accumulating detrimental effects in that time. Death as a result of those

effects is typically labeled a natural death by the pathologist. Drugs can also alter a person’s judgment and psychomotor

skills to the point that a fatal accident occurs. Drugs are also often at the source of acts of violence that result in death.

Quick Review

• A primary objective of the autopsy is to determine the cause of death. The cause of death is that which initiates the

series of events ending in death.

• The most important determination in a violent death is the character of the injury that started the chain of events that

resulted in death.

• Some of the more common causes of death are blunt force injury, sharp force injury, asphyxia, gunshot wound, and

substance abuse.

• A blunt force injury is caused by a nonsharpened object such as a bat or pipe. A blunt force injury can abrade tissue

or can cause a contusion arising from bleeding from tiny ruptured blood vessels within and beneath the skin.

• Sharp force injuries occur from weapons with sharp edges, such as knives or blades.

• Asphyxia encompasses a variety of conditions that involve interference with the intake of oxygen. For example,

death at a fire scene is caused primarily by the extremely toxic gas, carbon monoxide.

• Gunshot wounds originate from projectiles fired by a firearm. The distance a weapon was fired from a target is one of

the most important factors in characterizing a gunshot wound.

• Because drug abuse is so common, a forensic pathologist will routinely order toxicological tests for the presence of

drugs in nearly all autopsies.

THE AUTOPSY

An autopsy , in its broadest definition, is simply the examination of a body after death (i.e., a postmortem examination). The

autopsy can be further described as one of two types: a clinical/hospital autopsy or a forensic/medicolegal autopsy. The

clinical/hospital autopsy focuses on the internal organ findings and medical conditions. Its purpose is to confirm the clinical

diagnoses, the presence and extent of disease, any medical conditions that were overlooked, and the appropriateness and

outcome of therapy. In contrast, the goal of a forensic/medicolegal autopsy is to determine the cause of death and confirm the

manner of death, often to be used in criminal proceedings. The forensic autopsy usually emphasizes external and internal

findings while developing meaningful forensic correlations between sustained injuries and the crime scene (see Figures 6-7

and 6-8 ).

autopsy

A surgical procedure performed by a pathologist on a dead body to ascertain—from the body, organs, and bodily fluids—the

cause of death.

All the steps of the forensic autopsy must be carefully documented and photographed. The documentation should include

date, time, place, by whom the autopsy was performed, and who attended the autopsy. Photographs of the injuries, complete

with a scale, and descriptions of each photograph’s location are important when correlating external wounds with internal

damage. Negative photographs—photographs of uninjured parts of the body—are also important. The autopsy report and

photographs are so important because, once the body is buried, no further evidence can be collected and no additional

findings can occur.

EVIDENCE FROM THE AUTOPSY

The search for physical evidence must extend beyond the crime scene to the autopsy room of a deceased victim. Here, the

medical examiner or pathologist carefully examines the victim to establish the cause and manner of death. As a matter of

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routine, tissues and organs are retained for pathological and toxicological examination. At the same time, arrangements must

be made between the examiner and investigator to secure a variety of items that may be obtainable from the body for

laboratory examination. The following are among the items to be collected and sent to the forensic laboratory:

• Victim’s clothing

• Fingernail scrapings

FIGURE 6-7 An autopsy suite.

FIGURE 6-8 Tools used for an autopsy.

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• Combings from head and public areas

• Blood (for DNA typing purposes)

• Vaginal, anal, and oral swabs (in sex-related crimes)

• Bullets recovered from the body

• Swabs of body areas suspected of being in contact with DNA arising from touching or saliva

• Hand swabs from shooting victims (for gunshot residue analysis)

These items of evidence should be properly packaged and labeled like all other evidence. Once the body is buried, efforts at

obtaining these items may prove difficult or futile. Furthermore, a lengthy time delay in obtaining many of these items will

diminish or destroy their forensic value.

EXTERNAL EXAMINATION

The forensic autopsy consists of an external examination and an internal examination. The first steps taken for the external

examination include a broad overview of the condition of the body and the clothing. Obvious damage to the clothing should

be matched up to injuries on the body. General characteristics of the body should be noted, including sex, height, weight,

approximate age, color of hair, and physical condition. The presence of tattoos and scars, as well as puncture and track

marks, are noted. All evidence of apparent medical intervention must be carefully noted, described, and photographed

because occasionally these may be misinterpreted, especially chest tube insertions and emergency cardiac punctures. The

mouth and nose is examined for the presence of vomit and/or blood and trace evidence, and the ears are examined for blood.

Any irritations in the nasal cavity can be indicative of drug sniffing.

Often, paper bags are place over the hands at the crime scene until it is time to examine them. This prevents contamination

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and possible loss of trace evidence, such as hairs and fibers. This preservation of evidence can play an important role in

identifying a suspect. A victim will sometimes have skin and DNA under his or her fingernails from fighting with the

assailant.

The external examination also consists of classifying the injuries. This includes distinguishing between different types of

wounds, such as a stab wound versus a gunshot wound. The injuries that are examined may include abrasions, contusions,

lacerations, and sharp injury wounds. Hemorrhages in the eyelids (petechiae) are also essential to note, as they can be

indicative of strangulation. Attention is also paid to the genitalia, especially in cases where sexual abuse is suspected. In

these cases, vaginal, oral, and rectal samples are taken.

The discharge from a firearm will produce characteristic markings on the skin. This discharge is a combination of soot and

gunpowder. It will leave markings called stippling or tattooing around the bullet hole. The stippling can be analyzed in terms

of its span and density in order to approximate the range of fire. The range of fire may prove to be the most important factor

in distinguishing a homicide from a suicide.

X-ray examinations can be very useful in the autopsy process. They are most commonly performed in gunshot wound cases

and stab wound cases. Even if the bullet, knife, or other piercing weapon is recovered outside the body, an X-ray will identify

any fragments still inside the body. An X-ray will also help determine the path of the projectile or sharp utensil. X-rays can

also be very helpful in cases where the victim was beaten, especially situations in which the victim is a child: An X-ray can

show past bone fractures and a possible pattern of abuse.

INTERNAL EXAMINATION

The dissection of the human body generally entails the removal of all internal organs through a Y-shaped incision beginning

at the top of each shoulder and extending down to the pubic bone. Performing the internal examination entails weighing,

dissecting, and sectioning each organ of the body. When required and in accordance with jurisdictional rules, microscopic

examination of the sectioned organs is conducted, which can help in determining the cause of death. For example,

microscopic examination of lungs and liver can confirm chronic intravenous drug abuse. Examination of the cranium

requires cutting an incision from behind one ear to the other, peeling the scalp upward and backward, and sawing of the skull

in a circular cut; then the skull cap is removed to reveal the brain, as shown in Figure 6-9 .

Special care is taken to identify any preexisting conditions or malformations in the organs that might have contributed to the

death of the victim. Pulmonary edema (fluid accumulation in the lungs) is frequently found in victims of chronic cocaine and

amphetamine abuse. Heart malformations may cause suspicious death in an otherwise healthy individual.

Special attention is paid to the digestive tract if poisoning is suspected. The stomach can show partially digested or dissolved

pills. Chemical analyses can also be carried out to show signs of poisoning. The amount of pills or tablets in the stomach can

aid in the determination of manner of death as well. It is not always a sure sign, but typically it is unlikely that a person will

accidentally swallow a large number of pills. This would suggest suicide rather than an accidental overdose. Stomach

contents may reveal the deceased’s last meal. The extent of digestion can help with determining the time of death.

Toxicology

The internal examination is also where toxicological specimens are taken. These include samples of blood, stomach content,

bile, and urine. All bile in the gallbladder and all stomach content are collected. In addition to these, brain matter, liver, and

vitreous humor are also gathered. These specimens can play especially large roles in cases where poisoning or drug abuse is

suspected.

FIGURE 6-9 A brain during autopsy.

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Blood is often tested to determine the presence and levels of alcohol and drugs. Blood should be taken from areas of the body

where there is the least chance of contamination. Blood should never be collected from body cavities, where it may be

contaminated from adjacent structures. Many changes occur in the body after death, and these changes can alter the drugs

present in the system at the time of death. This can make interpreting how much of a drug was present, if any at all, a very

challenging task. Some drugs redistribute or reenter the blood after death and thus may complicate the interpretation of

postmortem blood levels of these drugs. This phenomenon is known as postmortem redistribution . For this reason, it is best

to collect blood at distant areas of the body to allow the toxicologist to compare the agreement of the drug concentrations

found. The ideal location to retrieve the blood is internally, directly from the inferior vena cava (the large vein inside the

lower abdominal region, which receives its blood from the femoral veins) using a syringe. Where postmortem redistribution

of drugs may have occurred, blood should also be collected at autopsy from the superior venous system directly above the

heart.

For illicit as well as legal substances, it is necessary to know what levels are indicative of therapeutic use and what levels

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indicate toxicity of a given substance. Much information regarding therapeutic versus toxic drug levels has been published.

This data can help pathologists and toxicologists ascertain the cause of death. Most drug-related deaths are quite apparent

from the blood concentrations of alcohol and/or a drug found in the postmortem toxicological report. (Note that depressant

drugs will act in concert with alcohol.) However, in some cases of drug-induced death, drug levels may not always provide

evidence. Cocaine is a prime example of this. Cocaine-induced sudden death is an event with an incubation period. Structural

alterations of the cardiovascular system are required, and such alterations take months, or perhaps years, of chronic cocaine

use. In these individuals, death and toxicity may occur after the use of even a trivial amount of the drug.

Unlike drug analyses, general testing for poisons is not a routine procedure carried out by the pathologist. However, if a

specific poison is suspected, a particular test must be performed. A body that displays a cherry-red discoloration often leads a

pathologist to suspect carbon monoxide poisoning. The pathologist would then perform a toxicological test of the blood.

Poisoning by cyanide could also produce a pinkish discoloration. Often, cyanide toxicity will show additional signs, such as

a distinct smell of burnt almonds. Corrosion around the lips of a victim may lead to a suspicion of ingesting an acid or

alkaline substance.

Quick Review

• An autopsy, in its broadest definition, is simply the examination of a body after death.

• The forensic autopsy consists of an external examination and an internal examination.

• The first steps taken for the external examination include a broad overview of the condition of the body and the

clothing.

• The external examination also consists of classifying the injuries. This includes distinguishing between different

types of wounds, such as a stab wound versus a gunshot wound.

• The dissection of the human body generally entails the removal of all internal organs through a Y-shaped incision

beginning at the top of each shoulder and extending down to the pubic bone.

• The internal examination entails weighing, dissecting, and sectioning each organ of the body.

• Blood is often routinely tested to determine the presence and levels of alcohol and drugs.

• Some drugs redistribute or reenter the blood after death and thus may complicate the interpretation of postmortem

blood levels of these drugs.

MyCrimeKit WebExtra 6.1

See How an Autopsy Is Performed www.mycrimekit.com

MANNER OF DEATH

The manner of death relates to the circumstances that led to the fatal result and is the culmination of the complete

investigation, including the determination of cause of death. The certification of the circumstances and manner of death is the

responsibility of the coroner’s and medical examiners’ offices. The manner in which death occurred is classified in death

certifications as one of five categories: homicide, suicide, accidental, natural, or undetermined .

manner of death

A determination made by a forensic pathologist of the cause of death. Five broad categories are homicide, suicide, accidental,

natural, and undetermined.

HOMICIDE

Although there is no universal agreement on its definition, generally the term homicide , as certified by coroner’s and medical

examiners’ offices, is defined as a nonaccidental death resulting from grossly negligent, reckless, or intentional actions of

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another person. Both the cause and manner of death, as certified by the coroner’s/medical examiners’ offices, can become the

subject of expert debate during any subsequent judicial proceedings. However, this does not result in a revision of the death

certification unless there has been negligence on the part of the certifying offices.

If the pathologist was unable to go to the scene, he or she should receive adequate information detailing the conditions of the

scene from coroner/medical examiner investigators and law enforcement personnel. This information should include how the

body was discovered as well as when and where. It is also an important first step for investigators to make note of the algor

mortis, livor mortis, and/or rigor mortis of the body at the scene. These will help to determine time of death.

SUICIDE

Suicide is the result of an individual taking his or her own life with lethal intention. For a determination of suicide, it must be

demonstrated that the individual carried out the act alone. If there is any doubt about the intentions of the victim, the death is

not classified as a suicide; the death is ruled as an accident or even as undetermined. The most common methods of suicide

include self-inflicted gunshot wounds, hanging, and drug overdosing. Although drug abuse is deliberately committed by a

victim, it is not considered suicide unless it was clearly intended as a lethal act.

There are various challenges associated with discriminating suicide from an accident or even homicide. The victim’s

personal history, including his or her psychiatric history, becomes relevant. Suicidal threats or past attempts would give

obvious evidence of a suicide as opposed to an accident. In all cases of suspected suicide, a thorough search of the victim’s

possessions should be made to locate a suicide note.

Multiple gunshot wounds might lead one to suspect homicide. However, a person that is committed to ending his or her own

life may take several shots if the wounds are not instantly fatal. It is imperative to confirm that it is physically possible that

the victim could inflict the wounds. There are a few areas of the body that strongly point toward homicide. These are areas

that are not easily accessible to the victim’s own reach. For example, anywhere on the back of a victim is difficult and

sometimes impossible for the victim to have shot by his or her own hand. This is especially true if the wound was made in

the back of the head. For suicides, the most common shot is to the temple of the head. The mouth, forehead, and chest are

also common.

Also, if the wound was immediately incapacitating, the weapon should be present. Blood spatter analysis should be

consistent with the proposed order of events. All victims involved in gunshot cases should have their hands swabbed for

gunshot residue.

ACCIDENTAL

In all deaths that are ruled accidental, there must not be intent to cause harm through gross negligence on the part of a

perpetrator or the victim. Traffic accidents make up a large percentage of accidental deaths, followed by drug overdoses and

drownings. The surviving driver may have vehicular homicide charges brought against him or her, especially if the driver is

determined to have been driving under the influence of drugs or alcohol. In this case, the official manner of death certified on

the death certificate in many jurisdictions would be vehicular homicide .

All cases that have the possibility of being a ruled an accident should have toxicological analyses carried out. The presence

of drugs and/or alcohol in the victim’s system can potentially affect the determination. Also, the pathologist should be aware

that some events might be disguised as accidents to cover up a homicide or suicide. For example, bodies recovered from a

house fire might show evidence that the victims were dead before the fire started. This evidence might include a lack of soot

in the victim’s airways or no indication of elevated levels of carbon monoxide. This scenario, although not common,

illustrates how the autopsy and scene can apparently not correlate with each other. No matter how obvious a scene may

appear, the two should always correspond with one another. Cases of electrocution are generally ruled as accidents, but this

may be difficult to prove. High-voltage electrocutions will usually leave burns on the body. Low-voltage electrocutions,

however, may show little to no signs of trauma. The scene then becomes crucial in ascertaining the events surrounding the

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death.

The determination of manner of death in drownings (accidental, suicidal, or homicidal), falls (accidental, pushed, or

deliberate), and asphyxiations can be exceedingly difficult, and therefore the investigation in all of its components becomes

much more important than the autopsy.

NATURAL CAUSES

The differentiation between the categories of manner of death can be difficult to make. The distinction between natural and

accidental deaths can pose challenges. The classification of natural death includes disease and continual environmental

abuse. This abuse can encompass various events, such as chronic drug and alcohol abuse or longtime exposure to natural

toxins or asbestos. Again, although drug abuse is deliberately committed by the victim, a death caused by drug use is not

considered suicide unless it is clear that drugs were taken as an intentionally lethal act. Acute ethanol intoxication can be

ruled as either natural or accidental depending on the circumstances. If the victim suffers from chronic alcoholism, the death

is ruled to be natural. If the victim is a teenager experimenting with alcohol for the first time, the death is ruled an accident.

UNDETERMINED

A death is ruled to be undetermined only when a rational classification cannot be established. This can happen when the

mechanism that caused the death cannot be determined by a physical finding at the autopsy or because of the absence of

meaningful findings in the subsequent toxicological and microscopic examinations.

Quick Review

• The manner in which death occurred is classified in death certificates as one of five categories: homicide, suicide,

accidental, natural, or undetermined.

• Homicide is generally defined as a nonaccidental death resulting from grossly negligent, reckless, or intentional

actions of another person.

• Suicide is the result of an individual taking his or her own life with lethal intention. Although drug abuse is

deliberately committed by a victim, it is not considered the cause of suicide unless it was clearly intended as a lethal

act.

• In all deaths that are ruled accidental, there must not be intent to cause harm through gross negligence on the part of a

perpetrator or the victim. Traffic accidents make up a large percentage of accidental deaths, followed by drug

overdoses and drownings.

• The classification of natural death includes disease and continual environmental abuse. This abuse can encompass

various events, such as chronic drug and alcohol abuse or longtime exposure to natural toxins or asbestos.

• An undetermined cause of death arises when the cause of death cannot be determined by a physical finding at the

autopsy or because of the absence of meaningful findings in the subsequent toxicological and microscopic

examinations.

ESTIMATING TIME OF DEATH

A pathologist can never give an exact time of death. However, there are many characteristics that the examiner can analyze in

order to arrive at an approximate time of death. Some features can give a very probable time of death, but others are

extremely variable. Witnesses can serve to reconstruct the events leading up to the death and the incidents that occurred after

the death, along with the times when they occurred, but a single witness’s account alone is not enough to make an accurate

determination. The chemical and physical changes that occur after death must also be examined.

ALGOR MORTIS

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After death the body undergoes a process in which it continually adjusts to equalize with the environmental temperature. This

process is known as algor mortis . An algor mortis determination must be performed at the scene as early as possible. The

first step is to determine as best as possible what the environmental temperatures may have been prior to discovering the

body. Then the environmental temperature and the bilateral axillary and/or ear canal temperatures are recorded at the crime

scene (rectal temperatures are usually too disruptive at the scene). The cooling rate of a typical body can be used to estimate

the time of death. At average ambient temperatures of 70°F -72°F, the body loses heat at a rate of approximately of 1.0°F to

1.5°F per hour until the body reaches the ambient or room temperature. However, the rate of heat loss is influenced by

factors such as ambient temperature, the size of the body, and the victim’s clothing. Because of such factors, this method can

only approximate the amount of time that has elapsed since death.

algor mortis

A process that occurs after death in which the body temperature continually cools until it reaches the ambient or room

temperature.

FIGURE 6-10 Livor mortis.

LIVOR MORTIS

Another condition that begins when circulation ceases is livor mortis . When the human heart stops pumping, the blood

begins to settle in the parts of the body closest to the ground. As shown in Figure 6-10 , the skin becomes a bluish-purple

color in these areas. The onset of this condition begins twenty minutes to three hours after death and under average

conditions continues for up to sixteen hours after death, at which point all lividity, or coloring, is fixed. Initially, lividity can

be pressed out of the vessels when the skin is pressed, that is, lividity can be “blanched.” With time, coloring becomes

“fixed” in the vessels, beginning in the most dependent (lowest) areas and progressing to the least dependent areas, then

finally no blanching can be elicited anywhere. In any case, levels of lividity are tested at the scene with regard to whether it

is completely fixed, blanches when subjected to light pressure, or blanches when subjected to significant pressure. A range of

time of death can be estimated if at least some of the lividity is still blanching. However, the environmental temperature and

the rate of body temperature decline (i.e., algor mortis) directly affect the rate of fixation of lividity and therefore must be

taken into account when attempting to estimate time of death from lividity.

livor mortis

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A medical condition that occurs after death and results in the settling of blood in areas of the body closest to the ground.

Different lividity patterns in a body may indicate that the body was moved after death, but before livor mortis had fully fixed.

The skin does not become discolored in areas where the body is restricted by either clothing or an object pressing against the

body. This information can be useful in determining whether the victim’s position was changed after death. Livor that is a

deep purple is often seen in cases where the victim suffered asphyxia or heart failure.

RIGOR MORTIS

FIGURE 6-11 Rigor mortis in the arms of a decedent.

Immediately following death, a chemical change occurs in the muscles that causes them to become rigid, as shown in Figure

6-11 . This condition, rigor mortis , evolves over the first twenty-four hours under average temperature and body conditions.

This rigidity subsides as time goes on, however, and disappears after about thirty-six hours under average conditions. Rigor

will develop in the position that the body was in at the time of death, essentially freezing the body in that pose. Discovering a

body in a position that defies gravity is a likely indicator that the body was moved after death.

rigor mortis

A medical condition that occurs after death and results in the stiffening of muscle mass. The rigidity of the body begins

within twenty-four hours of death and disappears within thirty-six hours of death.

Although rigor mortis can roughly indicate a time of death, there are factors that can alter this determination. An

environment that is hot can speed up the process significantly. Conditions that affected the body before death, such as

exercise or physical activity, can also speed up the process. Because rigor mortis occurs as a result of the muscles stiffening,

individuals with decreased muscle mass may not develop rigor completely. Examples of these individuals may be infants or

elderly or obese persons.

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POTASSIUM EYE LEVELS

Another approach helpful for estimating the time of death is to determine potassium levels in the decedent’s ocular fluid, that

is, the fluid within the eye, also known as the vitreous humor . It is important to draw a clean, bloodless vitreous sample from

one eye with a syringe as soon as possible at the scene, then draw a second sample from the other eye an hour or two later.

After death, cells within the inner surface of the eyeball release potassium into the ocular fluid. By analyzing the amount of

potassium present at various intervals after death, the forensic pathologist can determine the rate at which potassium is

released into the vitreous humor and use it to approximate the time of death. However, the rate of potassium release also is

dependent on ambient temperatures.

STOMACH CONTENTS

Special attention must be paid to the digestive tract. The identification of food items in the stomach may help to determine

the location of the decedent prior to death (during his or her last meal). The quantity, consistency, and color of bile, and the

degree of digestion of food in the stomach and its passage into the small intestine can help to determine the time of death.

The stomach also can contain partially digested or dissolved pills. Chemical analyses can be carried out to identify and

analyze substances found in the stomach. These can aid in the determination of cause, and manner of death.

DECOMPOSITION

Once decomposition has set in, the preceding methods of determining time of death are no longer of any use. After death,

two decomposition processes take place: autolysis and putrefaction. Autolysis is fundamentally self-digestion by cells’ own

enzymes, and its rate varies from organ to organ depending on the mechanism of death, the enzyme content of the respective

organs, the position of the body, and environmental factors. Putrefaction is decomposition carried out by microorganisms

such as bacteria. Putrefaction is accompanied by bloating, discoloration, and a foul smell caused by accumulating gases.

Again, the rate of putrefaction is dependent on the mechanism of death (for example, congestive respiratory versus sudden

cardiac death) allowing bacteria to spread from the bowel, presence or absence of infection, environmental temperatures and

humidity, degree of obesity, extent of clothing, and so on. Green discoloration often begins in the abdomen. Darker green or

purple discoloration follows on the face. The skin begins to blister with gas and then peel (called slippage ). The skin of the

hands and feet can actually detach and come off the body like a glove. This stage is also accompanied by bloating, which

causes the eyes to bulge and the tongue to protrude. The chest and extremities will then turn a green/purple discoloration and

bloat.

In the postmortem period of decomposition, a waxy substance called adipocere may form. Adipocere adds a white or gray

waxlike consistency to fatty tissues in the face and extremities that can take on a yellow to tan color. Typically, adipocere

takes about three months to develop.

Quick Review

• After death the body undergoes a process known as algor mortis in which it will continually adjust to equalize with

the environmental temperature.

• Another condition beginning when circulation ceases is livor mortis. When the human heart stops pumping, the blood

begins to settle in the parts of the body closest to the ground. The skin becomes a bluish-purple color in these areas.

• Immediately following death, a chemical change known as rigor mortis occurs in the muscles, causing them to

become rigid.

• Another approach helpful for estimating the time of death is to measure potassium levels in the ocular fluid.

• The identification of food items in the stomach may help to determine the location of the decedent prior to death,

during his or her last meal.

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Role of the Forensic Anthropologist

Forensic anthropology is concerned primarily with the identification and examination of human skeletal remains. Skeletal

bones are remarkably durable and undergo an extremely slow breakdown process that lasts decades or centuries. Because of

their resistance to decomposition, skeletal remains can provide a multitude of individual characteristics long after a victim’s

death. An examination of bones may reveal a victim’s sex, approximate age, race, height, and the nature of a physical injury.

forensic anthropology

The use of anthropological knowledge of humans and skeletal structure to examine and identify human skeletal remains.

RECOVERING AND PROCESSING REMAINS

FIGURE 6-12 Crime-scene site showing a pelvis partly buried in sand and a

femur lying across a revolver.

Courtesy Paul Sledzik/National Transportation Safety Board

Thorough documentation is required throughout the processes of recovery and examination of human remains. A site where

human remains are found must be treated as a crime scene (see Figure 6-12 ). These sites are usually located by civilians who

then contact law enforcement personnel. The scene should be secured as soon as possible to prevent any further alteration of

the scene. The scene should then be searched to locate all bones, if they are scattered, and any other items of evidence such

as footwear impressions or discarded items. There are many tools that can be useful when searching for evidence at a “tomb”

site, including aerial photography, metal detectors, ground-penetrating radar, infrared photography, apparatuses that detect

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the gases produced by biological decomposition, and so-called cadaver dogs that detect the odors caused by biological

decomposition. All items that are found must be tagged, photographed, sketched, and documented in notes. Once all bones

and other evidence are found, a scene sketch should be made to show the exact location of each item (preferably using global

positioning system [GPS] coordinates), and the spatial relationship of all evidence. Once the skeletal remains have been

recovered, they can be examined to deduce information about the identity of the decedent.

DETERMINING VICTIM CHARACTERISTICS

The sex of the decedent can be determined by the size and shape of various skeletal features, especially those of the pelvis

and skull, or cranium. Female pelvic bones tend to form a wider, more circular opening than that in a male pelvis because of

a woman’s child-bearing capabilities. The female sacrum (flat bone above the tailbone) is wider and shorter (see Figure

6-13[a] ) than a male’s; the length and width of the male sacrum are roughly equal (see Figure 6-13[b] ). The angle formed at

the bottom of the pelvis (i.e., subpubic angle) is approximately a right angle (90 degrees) in females, but it is acute (less than

90 degrees) in males. In general, male craniums are larger in overall size than those of females. A male cranium tends to have

a more pronounced brow bone and mastoid process (a bony protrusion behind the jaw) than a female cranium (see Figure

6-14 ). See Table 6.1 for a summary of the differing features of female and male skeletons from head to toe. These are typical

cases; not all skeletons may display the given characteristics to clearly indicate the sex of the decedent.

The method for determining the age of a decedent varies depending on the victim’s growth stage. For infants and toddlers,

age can be estimated by the length of the long bones (e.g., femur and humerus) when compared to a known growth curve.

Different sections of the skull also fuse together at different stages during early development, and the appearance of fused or

divided sections can be used to estimate the age of bones still in early developmental stages (see Figure 6-15 ). In infant

skeletons, formation of teeth can be used in age determination; this is based on the fact that permanent teeth start to form at

birth. If the skeletal remains belong to a child, the age of the decedent may be determined by observing the fusion or lack of

fusion of epiphyseal regions of bones such as those of the mandible (i.e., lower jaw), fingers, wrist, long bones, and clavicle

(see Figure 6-16 ). The average age at which each of these regions fuses is known and can be compared against the state of

the remains to provide a range of possible ages for the decedent. A child’s cranium may also be identified by its smaller size

and the presence of developing teeth (see Figure 6-17 ). After age 21, age is estimated by the level of change the surfaces of

the bones have undergone, especially in areas of common wear such as the pubic symphysis. The pubic symphyseal face

shown in Figure 6-18 is a raised platform that slowly changes over the years from a rough, rugged surface to a smooth, well-

defined area. See Table 6.2 for a summary of the skeletal closures by age. It is important to note that these are average ages

for closures; not all skeletons display closures at the given ages.

FIGURE 6-13 (a) Frontal shot of female pelvis and hips. This view shows the

wide, circular nature of the pelvic opening and the short, wide nature of the

sacrum. (b) Human male pelvis. This view shows the narrow pelvic opening

and long, narrow sacrum.

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(b) Giuliano Fornari © Dorling Kindersley

FIGURE 6-14 Male (left) and female (right) human skulls showing male

skull’s larger size and more pronounced brow bone.

Corbis RF

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TABLE 6.1 Summary of Skeletal Features by Gender

FEMALE MALE

Cranium (skull) Medium to large in size Large in size

Forehead High in height, vaulted, rounded Low in height, sloped, backward

Brow bone Diminished Pronounced

Mastoid process Diminished or absent Pronounced

Mandible (jaw) angle Obtuse (>90 degrees) Approximately right (90 degrees)

Pelvis opening Wide, circular Narrow, noncircular

Sacrum Short, wide, turned outward Approximately equal width/length, turned inward

Subpubic angle Approximately right (90 degrees) Acute (<90 degrees)

Femur Narrow, angled inward from pelvis Thick, relatively straight from pelvis

Overall skeleton Slender Robust

FIGURE 6-15 A lateral view of a fetal skull showing the separated bones of

the skull before they have had a chance to fuse.

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Ralph T. Hutchings

FIGURE 6-16 Colored X-rays of healthy human hands at 3 years (left) and at

20 years. Bones display in red, and flesh is in blue. The child’s hand has areas

of cartilage in the joints between the finger bones (i.e., epiphyseal areas),

where bone growth and fusion will occur. In the adult hand, all the bones are

present, and the joints have closed.

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SPL\Photo Researchers Inc.

FIGURE 6-17 The skull of a young child, with part of the jaw cut away to

show the developing teeth.

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Ralph T. Hutchings

FIGURE 6-18 The symphysis pubis shown magnified beneath human pelvic

bones.

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Pearson Education Custom Publishing

Although the categorization “race” has come under scrutiny and is difficult to define, forensic anthropologists use broad

classes to characterize the likely (but not definite) ancestry of skeletal remains. The possible racial ancestry of the decedent

can be assessed by the appearance of various cranial features on the skeletal remains. For example, eye orbits tend to be

circular in Mongoloid skeletons (i.e., of Asian descent), oval in Caucasoid skeletons (i.e., of European descent), and square

in Negroid skeletons (i.e., of African descent). The frontal plane of the cranium may also vary. The frontal plane of

Mongoloid craniums may be flat or projected outward, that of Caucasoid craniums is flat, and that of Negroid craniums is

projected outward. The nasal cavity tends to be small and rounded in Mongoloids, long and narrow in Caucasoids, and wide

in Negroids. Skeletal remains of decedents of Asian ancestry, including those of Native American descent, also tend to have

“scooped-out” or shovel-shaped incisor teeth. See Table 6.3 for a summary of the differing features of skeletons that can

indicate ancestry. These are typical cases; not all skeletons may display the given characteristics to indicate the ancestry of

the decedent.

The height of the victim when alive can be estimated by measuring the long bones of the skeleton, especially in the lower

limbs. Even partial bones can yield useful results. However, meaningful stature calculations from known equations must be

based on the determined sex and race of the remains. See Table 6.4 for examples of equations used to calculate the height of

the decedent from skeletal remains. These equations should yield estimations within 5 cm of actual height.

TABLE 6.2 Summary of Skeletal Closures by Age

AGE (MONTHS) CLOSURE

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AGE (MONTHS) CLOSURE

6-9 Mandible (jaw) fused

4-6 Humerus head bones fused

7-8 Pelvis frontal bones fused

4-16 Femur shaft sections built

9-13 Elbow bones fused

10 Finger bones fused

16-18 Femur head bones fused to shaft bones

18 Wrist bones fused

18-21 Humerus head bones fused to shaft bones

18-24 Sternum fused to clavicle

20-25 Pelvic bones fully formed

21-22 Clavicle fused

21-30 Labodial suture (rear of cranium) fused

24-30 Sacrum bones fused

30-32 Sagittal suture (center of cranium) fused

48-50 Coronal suture (front of cranium) fused

TABLE 6.3 Summary of Skeletal Characteristics Indicating Racial Ancestry

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EYE ORBITALS NASAL CAVITY INCISORS CRANIUM FRONTAL PLANE

Caucasoid Oval Long, narrow Smooth Flat

Mongoloid Circular Small, rounded Shoveled interior Flat or projected outward

Negroid Square Wide Smooth Projected outward

OTHER CONTRIBUTIONS OF FORENSIC ANTHROPOLOGY

A forensic anthropologist may create facial reconstructions to help identify skeletal remains. Facial reconstruction clay is

placed and shaped over the victim’s actual cranium, and it takes into account the decedent’s estimated age, ancestry, and sex

(see Figure 6-19 ). With the help of this technique, a composite of the victim can be drawn and advertised in an attempt to

identify the victim.

Forensic anthropologists are also helpful in identifying victims of a mass disaster such as a plane crash. When such a tragedy

occurs, forensic anthropologists can help identify victims using the collection of bone fragments. Usually, the identification

of the remains will depend on medical records, especially dental records of the individuals. However, definite identification

of remains can be made only by analyzing the decedent’s DNA profile, fingerprints, or medical records. Recovered remains

may still contain some soft tissue material, such as the tissue of the hand, which may yield a DNA profile for identification

purposes. If the tissue is dried out, it may be possible to rehydrate it to recover fingerprints also.

CASE FILES IDENTIFYING A SERIAL KILLER’S VICTIMS

The worst serial killer in the United States calmly admitted his guilt as he led investigators to a crawl space under his house.

There, John Wayne Gacy had buried 28 young men, after brutally raping and murdering them in cold blood. Because no

forms of identification were found with the bodies, the police were forced to examine missing-person reports for leads.

However, these boys and men were so alike in age, race, and stature that police were unable to individually identify most of

the victims. Clyde Snow, the world-renowned forensic anthropologist from Oklahoma, was asked to help the investigators

make these difficult identifications.

Snow began by making a thirty-five-point examination of each skull for comparison to known individuals. By examining

each skeleton, he made sure each bone was correctly attributed to an individual. This was crucial to later efforts because

some of the victims had been buried on top of older graves, mingling their remains. Once Snow was sure all the bones were

sorted properly, he began his in-depth study. Long bones such as the femur (thigh bone) were used to estimate each

individual’s height. This helped narrow the search in the attempt to match the victims with the descriptions of missing

people.

After narrowing the list of missing people to those fitting the general description, investigators consulted missing persons’

hospital and dental records. Evidence of injury, illness, or surgery and other unique skeletal defects of the victims were

matched to information in the records to make identifications. Snow also pointed out features that gave useful clues to the

victim’s behavior and medical history. For example, he discovered that one of Gacy’s victims had a healed fracture on his left

arm, and that his left scapula (shoulder blade) and arm bore the telltale signs of a left-handed individual. These details were

matched to a missing-person report, and another young victim was identified.

For the most difficult cases, Snow called in the help of forensic sculptor and facial reconstructionist Betty Pat Gatliff. She

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used clay and depth markers to put the “flesh” back on the faces of these forgotten boys in the hopes that someone would

recognize them after the photographs of the reconstructed faces were released to the media. Her efforts were successful, but

investigators found some families unwilling to accept the idea that their loved one was among Gacy’s victims. Even with

Gatliff ’s help, nine of Gacy’s victims remain unidentified.

TABLE 6.4 Equations for Height Calculation from Skeletal Remains

CAUCASOID NEGROID UNKNOWN ANCESTRY

Female

Height (cm) = femur length (cm) ×

2.47 + 54.10

Height (cm) = femur length (cm)

×2.28 + 59.76

Height (cm) = femur length (cm)

×3.01 + 32.52

Height (cm) = humerus length (cm)

×3.36 + 57.97

Height (cm) = humerus length (cm)

×3.08 + 64.67

Height (cm) = humerus length (cm)

×4.62 + 19.00

Male

Height (cm) = femur length (cm)

×2.32 + 65.53

Height (cm) = femur length (cm) ×

2.10 + 72.22

Height (cm) = femur length (cm)

×2.71 + 45.86

Height (cm) = humerus length (cm)

×2.89 + 78.10

Height (cm) = humerus length (cm)

×2.88 + 75.48

Height (cm) = humerus length (cm)

×4.62 + 19.00

FIGURE 6-19 Trooper Sarah Foster, a Michigan State Police forensic artist,

works on a three-dimensional facial reconstruction from an unidentified

human skull at Richmond Post in Richmond, MI.

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Quick Review

• Forensic anthropology is concerned primarily with the identification and examination of human skeletal remains.

• The gender of the decedent can be determined by the size and shape of various skeletal features, especially those of

the pelvis and skull, or cranium.

• The height of the victim when alive can be estimated by measuring the long bones of the skeleton, especially those in

the lower limbs.

Role of the Forensic Entomologist

The study of insects and their relation to a criminal investigation is known as forensic entomology. In practice, forensic

entomology is commonly used to estimate the time of death when the circumstances surrounding the crime are unknown.

This determination can be carried out by observing the stage of development of maggots or insects’ sequence of arrival.

forensic entomology

The study of insect matter, growth patterns, and succession of arrival at a crime scene to determine the time since death.

DETERMINING TIME OF DEATH

After decomposition begins, necrophilious insects, or insects that feed on dead tissue, are the first to infest the body, usually

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within 24 hours. The most common and important of these is the blowfly, recognized by its green or blue color. Blowfly eggs

are laid in human remains and ultimately hatch into maggots, or fly larvae, that consume human organs and tissues (see

Figure 6-20 ). Typically, a single blowfly can lay up to 2,000 eggs during its lifetime. The resulting larvae gather and feed as a

“maggot mass” on the decomposing remains. Forensic entomologists can approximate how long a body has been left

exposed by examining the stage of development of the fly larvae. This kind of determination is best for a timeline of hours to

approximately one month because the blowfly goes through the stages of its life cycle at a known sequence and in known

time intervals that span this period. By determining the most developed stage of fly found on the body, entomologists can

approximate the postmortem interval (PMI) , or the time that has elapsed since death (see Figure 6-21 ). Newly emerged

flies are of important forensic interest, as they indicate that an entire blowfly cycle has been completed on the decomposing

body. Likewise, empty pupal cases indicate that a fly has completed its entire life cycle on the body. Flies known as cheese

skippers are primarily found on human corpses in the later stages of decomposition, long after the blowflies have left the

corpse.

postmortem interval (PMI)

The length of time that has elapsed since a person has died. If the time is not known, a number of medical or scientific

techniques may be used to estimate it.

FIGURE 6-20 A scanning electron micrograph of two-hour-old blowfly

maggots.

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Time determinations based on the blowfly cycle are not always straightforward, however. The time required for each stage of

development is affected by environmental influences such as geographical location, climate, weather conditions, and the

presence of drugs. For example, cold temperatures hinder the development of fly eggs into adult flies. The forensic

entomologist must consider these conditions when estimating the PMI. Information about the arrival of other species of

insects may also help determine the PMI. The sequence of arrival of these groups depends mostly on the body’s natural

decomposition process. Predator insects generally arrive and prey on the necrophilious insects. Several kinds of beetles will

be found, either feeding directly on the corpse’s tissues or as predators feeding on blowfly eggs and maggots present on the

corpse. Next, omnivore insects arrive at the body. These insects feed on the body, on other insects, and on any surrounding

vegetation. Ants and wasps are an example of omnivore insects. Last comes the arrival of indigenous insects, such as spiders,

whose presence on or near the body is coincidental as they move about their environment.

OTHER CONTRIBUTIONS OF FORENSIC ENTOMOLOGY

Entomological evidence can also provide other pertinent information. In general, insects first colonize the body’s naturally

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moist orifices. However, if open wounds are present, they will colonize there first. Although the decomposition processes

may conceal wounds, colonization away from natural orifices may indicate the locations of wounds on the body. If maggots

are found extensively on the hands and forearms, for example, this suggests the presence of defensive wounds on the victim.

Insects that have fed on the body may also have accumulated any drugs present in the flesh, and analyzing these insects can

yield the identity of these drugs.

If resources allow, all insect evidence should be carefully collected by a forensic entomology expert. When this is not

possible, collection should be carried out by an investigator with experience in death investigation. The entire body and the

area where insect evidence was found must be photographed and documented before collection. Insect specimens should be

taken from each area on the body where they are found and labeled to show where they were collected from.

CASE FILES THE DANIELLE VAN DAM MURDER CASE

Sometime during the night of February 1, 2002, 7-year-old Danielle Van Dam disappeared from her bedroom in the Sabre

Springs suburb of San Diego, California. On February 27, three and a half weeks later, searchers found her naked body in a

trash-covered lot about 25 miles from her home. Because of the high degree of decomposition of the girl’s remains, the

medical examiner could not pinpoint the exact time of the girl’s death. Her neighbor, 50-year-old engineer David Westerfield,

was accused of kidnapping Danielle, killing her, and dumping her body in the desert. During the subsequent investigation,

Danielle’s blood was found on Westerfield’s clothes, her fingerprints and blood were found in his RV, and child pornography

was found on his home computer.

The actual time of the 7-year-old’s death became a central issue during the murder trial. Westerfield had been under constant

police surveillance since February 4. Any suggestion that Danielle was placed at the dump site after that date would have

eliminated him as a suspect. Conflicting expert testimony was elicited from forensic entomologists who were called on to

estimate when the body was dumped. The forensic entomologist who went to the dump site, witnessed the autopsy, and

collected and analyzed insects from both locations estimated that Danielle died between February 16 and 18. A forensic

entomologist and a forensic anthropologist both called to testify on behalf of the prosecution noted that the very hot, very dry

weather at the dump site might have mummified Danielle’s body almost immediately, thus causing a delay in the flies

colonizing the body.

The jurors convicted Westerfield of the kidnapping and murder of Danielle Van Dam, and a San Diego judge sentenced

David Westerfield to death. Danielle Van Dam’s parents filed and settled a wrongful death suit against Westerfield requiring

his automotive and homeowners’ insurance carriers to pay the Van Dams an undisclosed amount, reported to be between

$400,000 and $1 million.

FIGURE 6-21 Typical blowfly life cycle from egg deposition to adult fly

emergence. This cycle is representative of any one of nearly ninety species of

blowflies in North America.

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Quick Review

• Forensic entomologists can approximate how long a body has been left exposed by examining the stage of

development of fly larvae on the body.

• Information about the arrival of other species of insects may also help determine the postmortem interval. The

sequence of arrival of these groups depends mostly on the body’s natural decomposition process.

• In general, insects first colonize the body’s naturally moist orifices. However, if open wounds are present, they will

colonize there first.

CHAPTER REVIEW

• Forensic pathologists associated with the medical examiner’s or coroner’s office are responsible for determining the

cause of a an undetermined or unexpected death.

• Although both the coroner’s office and the medical examiners’ office are charged with investigating suspicious

deaths, only the pathologist is trained to perform an autopsy. The tasks of examining the body for cause and manner of

death and recording the results in the death certificate are all responsibilities of both offices.

• Protection of the body and the overall scene is of paramount importance, as is the ultimate removal of the body in a

medically acceptable manner.

• A primary objective of the autopsy is to determine the cause of death. The cause of death is defined as that which

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initiates the series of events ending in death.

• The most important determination in a violent death is the character of the injury that started the chain of events that

resulted in death.

• Some of the more common causes of death are: blunt force injury, sharp force injuries, asphyxia, gunshot wounds,

and substance abuse.