ABA Family Legal Guide

Criminal Justice

The Police and Your Rights

Criminal Charges

How does a grand jury work?

The jurors are summoned by the court to serve for a certain period of time, often many months, though they may be called into session only a few days a month. They may consider a number of cases during their term of service. They do not have to agree unanimously to issue an indictment, though state law often requires a vote of two-thirds or three-quarters of the jurors to indict. Typically, the prosecutor works very closely with the grand jury. Using the grand jury's broad investigative power to compel witnesses to appear and answer questions or submit documents, records, and other evidence, the prosecutor and jurors weigh the evidence and try to decide whether it is sufficient to issue an indictment against one or more persons.

Unlike trials, grand jury proceedings are secret. In many states, it is a crime to reveal information about a grand jury's proceedings. The public, the news media, and the person being investigated have no right to be present. The secrecy of the proceedings is intended to encourage witnesses to speak freely without fear of retaliation, such as threats from someone who does not like their testimony. It also protects the persons being investigated in the event that the evidence is deemed insufficient and an indictment isn't issued.

In most jurisdictions, people called to testify before a grand jury are not allowed to have their lawyers present in the grand jury room. In fact, the lawyers for the persons under investigation rarely play any role in grand jury proceedings, meaning that the grand jury makes its findings without hearing both sides of the case. Nor is a judge usually present during grand jury sessions, since normal rules of evidence don't apply in grand jury proceedings, making the role of the prosecutor all the more important.