Many people—like myself, before I became a lawyer—have no idea of the purpose a “grand jury” serves. In the United States, the grand jury was formally established through the creation of the Fifth Amendment to the United States Constitution. At its roots, the grand jury is supposed to function like a group of “neighbors” to help the state and society by bringing criminals to justice, while at the same time protecting the innocent from unjust accusations.

In the federal system, the grand jury decides whether someone should be formally charged, or indicted, for a serious crime. The grand jury may only evaluate evidence presented by the prosecutor—a specialized attorney of the United States government. Most states, like Alabama, use the same federal grand jury system to bring formal charges against criminal defendants.

A grand jury is a group of citizens, typically chosen from the same pool as trial jurors. Members are sworn by a court to hear evidence presented by the prosecutor. A grand jury is always composed of no less than 12 and no more than 23 people; in a federal court, the number is no less than 16 and no more than 23.

Unlike a trial jury, which determines whether a criminal defendant is innocent or guilty by unanimous vote, a grand jury can indict a defendant with a majority vote. Again, only the trial jury will decide whether a defendant is guilty or not guilty.

However, a grand jury will listen to evidence and decide if a suspect should be charged with a crime. As a result, the grand jury is only responsible for determining whether the State has probable cause to bring a charge against a person.

Because the grand jury's primary responsibility is to determine probable cause, it will not hear all the evidence or conflicting arguments associated with the case. The information provided to the grand jury is delivered by the prosecutor. In fact, the suspect's lawyer is not allowed to be present during presentation to the grand jury, and is not even allowed to know when the grand jury convenes. Although suspects themselves can testify in front of the grand jury, the State is under no obligation to notify the suspect that his case is being presented.

A grand jury will use the power of the court system to command, through the issuance of a subpoena, the delivery of evidence. Further, the grand jury may invite witnesses to provide testimony (a rare occurrence). There is no judge present during grand jury proceedings during the exchange of evidence and information. In fact, the entire grand jury proceedings are overseen by the prosecution. Once the grand jury has made its decision, it will either issue a “true bill,” meaning that the State has probable cause to charge the suspect, or a “no bill” which in effect dismisses the action.