How police officers and prosecutors initiate criminal cases.
A criminal case usually gets started with a police arrest report. The prosecutor then decides what criminal charges to file, if any. Some cases can then go to a grand jury for a criminal indictment or to a preliminary hearing, where a judge decides if there is enough evidence to proceed. Here's how this all works.
Arrest Reports and Criminal Charges
After an arrest, the police report goes to a prosecutor, whose job it is to initiate and prosecute cases. An arrest report summarizes the events leading up to the arrest and provides numerous details, such as dates, times, locations, and witness names and addresses (if available).
The prosecutor will typically either:
- determine that the case should be charged (as a felony or a misdemeanor), and file a “complaint” (the charging document may go by a different name) with the court
- decide that the case would be a felony and should go to a grand jury, which will decide what charges, if any, to file, or
- decide not to pursue the case.
A police officer specifies the crime or crimes that serve(s) as the basis for an arrest. Officers may recommend that the prosecution file additional charges, too. But prosecutors get to make the ultimate decision on what the charges will be. (See How do prosecutors decide whether to file criminal charges?)
A defendant typically learns what the formal charges will be at the first court appearance. To learn about that appearance, and how quickly after arrest it must occur, see Arraignment: Getting to Court.
Keep in mind that prosecutors' initial charges are subject to change. For example, a prosecutor may not make a final decision on what charges to file until after a preliminary hearing, which may take place more than a month after arrest.
The Role of a Grand Jury
If a felony is involved, prosecutors sometimes leave it to grand juries to decide whether charges should be filed. Grand juries are similar to regular trial juries (called "petit juries") in that they are made up of randomly selected individuals. The grand jurors listen to evidence and decide whether charges should be brought against an individual—that is, they decide whether to "indict" someone.
However, unlike petit juries, which sit only on one case, grand juries involve a time commitment that typically lasts between six and 18 months. The grand jurors may address many cases in the course of their service. In addition, these crucial differences exist:
- Petit jurors decide whether defendants are guilty. Grand juries decide whether there is enough evidence to warrant a trial.
- Grand juries meet in secret proceedings. Petit juries serve during public trials.
- Grand juries tend to be bigger than petit juries. In federal court, for example, they consist of 16 to 23 people. By contrast, a petit jury usually comprises six to 12 people.
- Petit juries generally have to be unanimous to convict a defendant. (But see Do criminal jury verdicts have to be unanimous?) Grand juries need not be unanimous to indict. In the federal system, for example, an indictment may be returned if 12 or more jurors agree to indict.
How a Grand Jury Works
When a prosecutor brings a case to a grand jury, he presents the jurors with a "bill" (the charges) and introduces evidence—usually the minimum necessary, in the prosecutor's opinion—to secure an indictment. The proceedings are secret; it is standard practice to call witnesses to testify against the suspect without the suspect or the suspect's lawyer present. But indicted suspects can sometimes later obtain transcripts of grand jury proceedings; the availability of a transcript is a big reason why prosecutors like to keep the evidence to the minimum.
Although prosecutors can also call suspects as witnesses, they typically don’t. When suspects are called, they often refuse to testify by invoking their privilege against self-incrimination under the Fifth Amendment to the U.S. Constitution.
If the grand jury decides to indict, it returns what is called a "true bill." If not, the grand jury returns a "no bill". But even if the grand jury returns a no bill, the case isn’t always closed. Prosecutors can return to the same grand jury with more evidence, present the same evidence to a second grand jury, or (in jurisdictions that give prosecutors a choice) bypass the grand jury altogether and file a criminal complaint.
How a Preliminary Hearing Works
Typically, if the prosecutor decides to file a complaint rather than present the case to a grand jury, and the case is a felony, the defendant is entitled to a preliminary hearing. At that hearing, the prosecutor must show that the state has enough evidence of the crime to warrant a trial.
But normally, if the case proceeds by grand jury indictment, no preliminary hearing need be held.
For much more on this stage of a case, see our section on Preliminary Hearings.
Get a Lawyer
Charging procedure differs significantly between federal and state court, from one state to another, and even between locales within the same state. If you’ve been arrested, consult an experienced criminal defense attorney. Such a lawyer will be able to fully explain the applicable law and guide you through the process. You can check out Nolo's trusted Lawyer Directory to find a criminal defense attorney in your area.