How Do Prosecutors Decide Which Cases to Charge?

Police officers arrest suspects, but prosecutors decide whether to file formal charges. Learn how it works.

By , UCLA Law School Professor
Updated by Rebecca Pirius, Attorney · Mitchell Hamline School of Law

When it comes to criminal charges, police generally make the arrests, and prosecutors file the criminal charges. The system separates police arrest powers and prosecution functions primarily to protect citizens. The prosecutor's charging decision is a check against the arbitrary exercise of police power. Prosecutors may file charges on all crimes for which the police arrested a suspect, file charges that are more or less severe than the charges leveled by the police, or decide not to file any charges at all. Read on to learn more about how these charging decisions are made.

Police Reports and Prosecutor Charging Decisions

Many criminal cases start with a 911 call. Police respond to the call and speak with the suspect, the victim, and any witnesses. If police have good reason (probable cause) to believe a crime has been committed and the suspect committed the crime, the police can arrest the suspect. Any victim, suspect, and witness statements, along with the police officer's observations, will go into a police report that makes its way to the prosecutor's desk.

Typically, prosecutors base their initial charging decisions on this police report and any documents sent to them by the arresting police officers. But police reports tend to be one-sided. They often recite what the police claim took place, along with victim, suspect, or witness statements that support the police theory. So, before making any charging decisions, prosecutors may also consider whether further investigation is needed, whether police may have acted unlawfully, and what motives the victim or witnesses may have had.

At the end of the day, prosecutors can file formal charges only if they believe the evidence will prove the suspect's guilt beyond a reasonable doubt—a much higher standard than the probable cause needed for an arrest.

How Do Prosecutors Decide Which Cases to Charge?

Even if the prosecutor believes they have a strong case, they can take a broader perspective in determining whether or not to pursue the charges. They have what is called "prosecutorial discretion." Prosecutors can look at all the circumstances of a case and the suspect, plus other factors pertaining to justice and public safety. For instance, prosecutors may consider:

  • the suspect's background and criminal past (if any)
  • whether the offense resulted in harm
  • whether the punishment fits the crime
  • whether the police acted with bias or engaged in improper conduct
  • the victim's wishes or motives
  • the impact of prosecution or no prosecution on the community
  • the limited resources of the prosecutors' office and fair use of them, and
  • whether remedies other than prosecution may be more appropriate in the case.

Many decisions come down to the prosecutor's sense of what justice requires in the case at hand. Prosecutors are supposed to both enforce the law and "do justice."

Doing justice means that a prosecutor occasionally decides not to prosecute a case (or files less severe charges) because the interests of justice require it, even if the facts of the case might support a conviction. For example, if an otherwise law-abiding person makes a one-time, foolish mistake, a prosecutor may decide that it would not serve any purpose to spend time and money prosecuting, especially when the chances that the person will re-offend are small.

Other Factors That Can Influence a Prosecutor's Charging Decision

Additional factors may come into play when it comes to a prosecutor's decision to file charges. Take, for example, the following.

Department Policies

Some prosecution offices adopt policies on certain types of crimes, often in response to community and political pressures, and these policies may dictate the prosecutor's approach to a case.

For example, an office may decide that arrests for driving under the influence of drugs or alcohol will always be taken to trial and not "plea bargained" down to a lesser offense. Or the head prosecutor could decide that their office won't prosecute low-level marijuana cases. As another example, an office might make prosecuting vehicle theft cases their top priority.

Political and Career Ambitions

Political and career ambitions may also influence prosecutors. Most head prosecutors are elected officials, and many of them view their position as a stepping stone to higher office. Public opinion and important support groups often affect their decisions on charges. For example, a prosecutor may file charges on every shoplifting case, no matter how weak, to curry favor with local store owners who want to get the word out that shoplifters will be prosecuted. Deputy or assistant prosecutors may feel that appearing tough will help their careers, either within the prosecutor's office or later if they want to become judges.

Why Do Prosecutors Choose Not to Prosecute Some Cases?

Prosecutors don't pursue every case put in front of them by police or victim complaints. All the factors listed above might convince a prosecutor to file charges, but they might also sway the prosecutor not to file charges or drop the charges.

Evidence suppressed. A prosecutor might drop the charges if evidence is tossed out of the case, and there's not enough additional evidence to support a conviction. For example, prosecutors might be forced to drop charges in a drug case if the judge suppresses evidence of the drugs based on an unlawful search by police.

Witness refuses to testify. If a victim or witness recants their statement or refuses to testify, this factor may impact the strength of the prosecution's case. A prime example of victims recanting occurs in domestic violence cases. If that statement was the key piece of evidence, the prosecutor may have some tough decisions to make on whether other evidence (like whether the doctor reports or witness statements) can prove the case.

Prosecutorial discretion may also come into play. The resources needed to take a first-time offender to court might not be justifiable when compared to a less costly and, possibly, more effective diversion program.

Small fish; big fish. Prosecutors sometimes use a small fish in a large criminal scheme to get to the big fish. For instance, a prosecutor might offer immunity to a drug dealer if they testify against the kingpins of the organization. Immunity means that the prosecutor agrees not to prosecute certain charges in exchange for the defendant's testimony or other assistance in getting the big fish.

Can Prosecutors Add Charges in a Case?

Yes, prosecutors can typically "amend" the charging documents by adding criminal charges. The new charges must be supported by the evidence. Amending the initial charges is common as new evidence is uncovered in a case.

Generally, any changes to the charges or complaint must be made before a plea is entered or trial begins. After that point, the prosecutor may need to get the judge's permission to add charges or add information to the complaint. A judge might decline the prosecutor's request to amend the charges if the defendant's rights would be prejudiced in some way (such as adding charges late in the game that might not allow the defendant adequate time to prepare a defense).

Speak to an Attorney

If you've been arrested or are being investigated by police, talk to a criminal defense attorney as soon as possible. Generally, it's best not to speak to investigators or police until you've spoken with an attorney. You could unwittingly say something that could be used against you.

Talk to a Defense attorney
We've helped 95 clients find attorneys today.
There was a problem with the submission. Please refresh the page and try again
Full Name is required
Email is required
Please enter a valid Email
Phone Number is required
Please enter a valid Phone Number
Zip Code is required
Please add a valid Zip Code
Please enter a valid Case Description
Description is required

How It Works

  1. Briefly tell us about your case
  2. Provide your contact information
  3. Choose attorneys to contact you