much power and authority to determine which cases are prosecuted and whether a person will face a harsh penalty or get away with a slap on the wrist?...

Why do prosecutors have so much power and authority to determine which cases are prosecuted and whether a person will face a harsh penalty or get away with a slap on the wrist? The answer is simple: "prosecutorial discretion." Under American law, government prosecuting attorneys have nearly absolute and unreviewable power to choose whether or not to bring criminal charges and what charges to bring.

There is no doubt that prosecutorial discretion is a necessary and important part of our system of justice — it allocates sparse prosecutorial resources, provides the basis for plea-bargaining and allows for leniency and mercy in a criminal justice system that is frequently harsh and impersonal. But it also places prosecutors in one of the most powerful positions in our criminal justice system. They literally have unchecked power to decide who will stand trial for crimes. Though most prosecutors use their discretion wisely and ethically, that discretion can also be misused to bring criminal charges — or to refuse to bring them — based on a prosecutor's own personal political beliefs.

So, what are the limitations on prosecutorial discretion discussed in the text?

Speaking of limitations on discretion... have you thought about how body cameras will limit police officer discretion?