What factors affect whether prosecutors decide to press charges against accused criminals?

Question

What factors affect whether prosecutors decide to press charges against accused criminals?

Answer 1

Whether there is a reasonable prospect of conviction, which entails having sufficient evidence.

If there is no evidence, the prosecutors will not even be eligible to have the matter be brought to trial; it would be a waste of court time if they did. Prosecution realizes this, and as such has careful discretion in who to indict.

Answer 2

The amount of evidence that can be used in a case.

Answer 3

It can often be arbitrary for the prosecutors on which to prosecute.

    Factors I can think of (not a complete list & not in any particular order of importance's) are:

    Violence and community outrage (got to get violent criminals murderers rapists off the streets).

    Money considerations as the courts are already overloaded.

    Probability of convictions. If a jury is going to blow the charge away why waste your time trying to nail this guy.

     Sometimes prosecutors offices have a particular agenda and have less of a problem with rape than white collar crime in certain neighborhoods.

          Of course no prosecutor in his right  mind could really admit to any of these as all laws broken are chargeable. When your local policeman saw you toss that cigarette butt or throw a piece of trash to litter the street $500.00 fine, but what makes the police-person let 99.9999%of these offenses pass?