The grand jury has a long and honorable tradition. It was recognized in the Magna Carta, the first English constitutional document, which King John granted in 1215 at the demand of his subjects. The first English grand jury consisted of twelve men selected from the knights or other freemen, who were summoned to inquire into crimes alleged to have been committed in their local community. Thus, grand jurors originally functioned as accusers or witnesses, rather than as judges.
The federal grand jury's function is to determine whether a person shall be tried for a serious federal crime alleged to have been committed within the district where it sits. If the grand jury finds that a crime has indeed been committed, the matter is sent to a petit jury to determine the guilt or innocence of those involved in the crime.
Matters may be brought to the attention of a grand jury in three ways:
- By the United States Attorney or an Assistant United Attorney.
- By the court that impaneled it.
- From the personal knowledge of a member of the grand jury or from matters properly brought to a member's personal attention.
In all these cases, the grand jury must hear evidence before taking action.
An ordinary trial consisting of twelve jurors, for criminal cases, or six jurors, for civil cases. A group of citizens listens to the evidence presented and determines the facts in dispute.