The present grand jury system evolved from the earlier ecclesiastical courts beginning in 1164 when King Henry II of England impaneled the first 16-man Grand Jury to remove criminal indictments from the hands of the church. In 1635, the first American Grand Jury was impaneled in the Massachusetts Bay Colony. By 1638, grand juries were present in all the colonies. These early Grand Juries began the practice of returning "presentments" which were primarily against public officials and different from criminal indictments.
Forty-two states use some form of the Grand Jury system. California is a State that allows prosecution to be initiated either by a Criminal Grand Jury indictment or by judicial preliminary hearing. The State of California impanels County Civil Grand Juries every year to conduct civil investigations of county and city government and to hear evidence to make recommendations or to decide to return indictments.
Secrecy and complete confidentiality are the sworn commitment of all Grand Jury members. This is to assure the protection and privacy of anyone coming before the jury with, or in response to, a complaint.