The Prosecutor's Role in Filing Charges
Many people are mistaken by the fact that the police officers are the ones that charge individuals. This is a false concept. What I try to tell all my clients is that the police officers are only investigators. Their role is to gather evidence. They also have authority to determine whether or not there is enough evidence to make an arrest or issue a citation. However, once the arrest has been made, the officer writes up a description of what happened, why an arrest was made and then hands the police report to the prosecutor.
If it involves a bigger crime that needs more information, it will go to a detective who will further investigate the crime before giving the information to the prosecutor. So in essence, the police officers and the detectives are information gatherers for the prosecutor.
From there, the prosecutor analyzes all of the information gathered and he makes a legal determination on whether or not there is enough probable cause to make a formal charge against the individual. We always tell our clients this because its true, but a big reason you want an attorney on your side and a good one at that, is so that you can have an individual investigate your side of the story.
The state has full-time employees investigating to prosecute individuals, so it is important to get an attorney on your side who can look into the facts as well, conduct their own investigation and ensure that your story gets told.
Probable cause is a more-than likely standard that the crime occurred. If it is more than 50% likely that the person committed the crime, they will make the charge. A judge will down the road make a determination of probable cause either at arraignment or a preliminary hearing to ensure that there is enough probable cause for the crime.
The prosecutors are held to a certain standards in the performance of their duty to the public. They have restraints under the due process clause and the Fifth amendment of the federal constitution to make sure that they do not prosecutor based on an unjustifiable standard such as race, religion or any other arbitrary classification.
Furthermore, prosecutors cannot use vindictiveness when charging an individual with a crime. For example, if an individual is charged with a crime, the prosecutor cannot add more charges just out of pure vindictiveness. Also, a prosecutor cannot charge an individual with additional crimes when a defendant tries to reverse a conviction.
Prosecutors are also held to the standard of ensuring that they give up all exculpatory evidence. Meaning that if there is evidence that could prove the innocence or guilt of the person with the crime committed, they must give that up. If they purposefully withhold that information then they would violate the individuals constitutional rights under the case U.S. v. Brady.
Also, if a defendant files a motion and makes a legal argument and the prosecutor knows of case law that the defendant has not pointed to, the prosecutor has a duty to disclose that case to the other party.