Most people think of a jury as twelve individuals who sit in judgment of defendants charged with a crime. While that is true, that kind of jury is called a Petit Jury. A Grand Jury, on the other hand, is a group of twenty-three citizens called together behind closed doors to investigate suspected criminal conduct. In Pennsylvania a Grand Jury, if called together by the Attorney General of the state, has multi-county jurisdiction --that is they can investigate criminal activity anywhere in the state of Pennsylvania. A Grand Jury called together by one of the sixty-seven district attorneys in the several counties of Pennsylvania has jurisdiction to investigate criminal activity in their particular county.