A Grand jury is defined as "a group of people who look at the evidence against someone who has been accused of a crime in order to decide if there should be a trial."[1]
Prosecutors present evidence to a grand jury, which decides whether there is probable cause to believe that a crime has been committed. Grand juries are made up of 16 to 23 people, who serve for a period of one month up to one year.
Grand jury sessions are held in private, usually not in the presence of the alleged criminal. Grand juries may request additional evidence such as witness testimony or documents to investigate on their own unimpeded by outside influence.[2]
The Supreme Court case United States v. Williams (1992) said that a grand jury is "a kind of buffer or referee between the Government and the people."[3] It decides if there is enough evidence to formally charge a suspect with a crime.