Grand jury

A group of citizens convened in a criminal case to consider the prosecutor's evidence and determine whether probable cause exists to prosecute a suspect for a felony. At common law, a group of persons consisting of not less than twelve nor more than twenty-four who listen to evidence and determine whether or not they should charge the accused with the commission of a crime by returning an indictment. The number of members on a grand jury varies in different states.

An American criminal justice procedure whereby, in each court district, a group of 16-23 citizens hold an inquiry on criminal complaints brought by the prosecutor and decide if a trial is warranted, in which case an indictment is issued. - (read more on Grand Jury)
  

A jury to determine whether the facts and accusations presented bythe prosecutor warrant an indictment and eventual trial of the accused, calledgrand