<P> The United States is one of only two common law jurisdictions in the world, along with Liberia, that continues to use the grand jury to screen criminal indictments . Generally speaking, a grand jury may issue an indictment for a crime, also known as a "true bill," only if it finds, based upon the evidence that has been presented to it, that there is probable cause to believe that a crime has been committed by a criminal suspect . Unlike a petit jury, which resolves a particular civil or criminal case, a grand jury (typically having twelve to twenty - three members) serves as a group for a sustained period of time in all or many of the cases that come up in the jurisdiction, generally under the supervision of a federal U.S. attorney, a county district attorney, or a state attorney - general and hears evidence ex parte (i.e. without suspect or person of interest involvement in the proceedings). </P> <P> While all states in the U.S. currently have provisions for grand juries, only half of the states actually employ them and twenty - two require their use, to varying extents . The modern trend is to use an adversarial preliminary hearing before a trial court judge, rather than grand jury, in the screening role of determining whether there is evidence establishing probable cause that a defendant committed a serious felony before that defendant is required to go to trial and risk a conviction on those charges . </P>

What are the duties of the grand jury in a criminal case
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