How Does a Grand Jury Work?

The grand jury plays an important role in the criminal process — but not one that involves a finding of guilt or punishment of a party. Instead, after the presentation of the prosecution's case, the grand jury will decide whether to bring an indictment against a potential defendant. Indictments bring formal charges for felony cases. They're followed by an arraignment for the criminal charges.

This article provides an overview of the following:

• How grand jury hearings work
• Differences between a grand jury and a preliminary hearing
• What happens after the grand jury's decision

The use of grand juries in the criminal justice system comes from the Fifth Amendment of the U.S. Constitution. It applies to felony offenses punishable by death or other infamous crimes punishable by imprisonment for more than a year. However, they're not used in some cases if there are only low-level felony charges or misdemeanor criminal cases.

Grand Jury Proceedings

Like trial jurors, grand jurors are citizens selected randomly from voter registrations and other sources. They may serve for up to 18 months but only need to appear in court for a few days out of every month. Regular trial juries consist of six or 12 people. In the federal system, a grand jury ranges from 16 to 23 people.

Unlike public criminal court proceedings, grand juries convene in secret. Grand juries proceed in strict confidence for two primary purposes:

• Witnesses can speak without fear of retaliation.
• It protects the potential defendant's reputation if the jury decides not to indict.

No judge, public defender, or criminal defense attorney is in the grand jury room when the prosecutor is presenting evidence. The prosecutor explains the law to the jury and works with them to gather evidence and hear witness testimony.

A prosecutor must not mislead the grand jury and should remain fair following the rules of evidence. The prosecutor's office is not permitted to present evidence obtained in violation of a defendant's constitutional rights. However, a grand jury can issue subpoenas and has broad power to see and hear almost anything the members would like.

How Does a Grand Jury Differ from a Preliminary Hearing?

While all states have provisions in their laws that allow for grand juries, about half of the states don't use them unless there is a serious felony charge. Courts often use preliminary hearings before adversarial criminal trials. As with grand juries, preliminary hearings determine whether there is enough evidence for a criminal suspect to stand trial.

The standard of proof at this stage is lower than at trial, which requires proof beyond a reasonable doubt. A judge uses probable cause, which is a reasonable basis for prosecution based on objective facts that the defendant likely committed a crime.

Unlike a grand jury, a preliminary hearing is usually open to the public. It involves lawyers on both sides and a judge. The prosecution must show sufficient evidence to proceed to trial, including the introduction of evidence or witness testimony (e.g., from the investigating law enforcement or the police officer whose sworn affidavit was the basis for a search warrant).

Preliminary hearings are not always required. A defendant can waive the hearing; however, this should only be done after consulting an experienced defense attorney and carefully weighing their legal advice. The criminal case will be dismissed if a judge finds no probable cause at this pretrial stage.

The prosecution can always refile once they obtain more evidence. On the other hand, if the prosecutor succeeds at the preliminary, the defendant may be more amenable to a plea agreement.

The Grand Jury's Decision and a Prosecutor's Discretion

At least 16 (out of 23) grand jurors must be present for a vote, and a unanimous decision is not required. At least 12 members must concur to indict a defendant under the Federal Rules of Criminal Procedure. In states that utilize grand juries, the number of members required for an indictment varies between a simple majority and a supermajority (two-thirds or three-quarters agreement).

If a grand jury chooses not to indict, a prosecutor may still bring the defendant to trial if they think there is a strong enough case. But it will be an uphill battle. Grand jury proceedings are often a valuable test run for prosecutors in deciding to bring a case.

However, with a grand jury indictment, the trial will likely begin more quickly. After receiving the true bill (the signed decision by the grand jury foreperson), the prosecutor can skip the preliminary hearing and proceed directly to trial.

Questions About How a Grand Jury Works in Your State? Get Answers from an Expert

Are you or someone you know facing a possible grand jury? Do you have more questions about how a grand jury works and how you can protect your constitutional rights?

An experienced criminal law attorney in your state will have detailed information about the grand jury process where you live. They can also ensure your interests are protected before, during, and after trial. Get in touch with a criminal defense lawyer in your area to learn more.