Grand Jury

A grand jury is a body of laypeople empanelled by a court to review evidence presented by a prosecutor and determine whether probable cause exists to issue an indictment—a formal criminal charge. Unlike a petit (trial) jury, which decides guilt or innocence, a grand jury does not determine criminal liability; it only screens whether a case should proceed to trial.

The institution traces back to medieval England, formalized in the Assize of Clarendon (1166) under Henry II, and was carried into American law via the colonies. In the United States, the Fifth Amendment to the Constitution requires that "no person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury," except in military cases. The Supreme Court in Hurtado v. California (1884) held that this requirement does not bind state governments, so roughly half of U.S. states use grand juries while others rely on prosecutor-filed informations reviewed at a preliminary hearing.

Key features:

• Size: U.S. federal grand juries consist of 16–23 jurors; at least 12 must concur to indict (Federal Rule of Criminal Procedure 6).
• Secrecy: Proceedings are closed to the public and the accused. Witnesses generally appear without counsel present in the room.
• Prosecutor-led: Only the government presents evidence; there is no defense rebuttal, which has drawn the long-running critique—attributed to former New York judge Sol Wachtler—that a prosecutor could "indict a ham sandwich."
• Investigative power: Grand juries can subpoena documents and testimony, making them a tool for complex inquiries into public corruption, organized crime, and national-security matters.

Outside the U.S., grand juries have largely been abolished. England and Wales ended the practice in 1933 (completed by the Administration of Justice Act 1933); Canada abolished it by 1984. They remain a distinctive feature of American criminal procedure and a recurring subject of reform debate.