There are two types of juries that you might encounter when you are charged with a criminal offense a grand jury and a petit jury. The grand jury is a selection of jurors who will decide whether or not to indict (charge) a suspect, while a petit jury decides the guilt or innocent of a defendant during a public trial proceeding.
A grand jury is a type of common law jury; responsible for investigating alleged crimes, examining evidence, and issuing indictments. The grand jury can compel witnesses to testify. During the proceeding, the defendant and his or her counsel are generally not present. The grand jury's decision is either "true bill" or "no true bill." Grand juries are part of the system of checks and balances that prevents prosecutors from harassing citizens with groundless prosecution. Before a defendant is ever forced to defend himself, the grand jury must find a "true bill" and issue an indictment.
Grand juries are required by the US federal government for "capital or infamous cases", according to the Fifth Amendment to the United States Constitution.
A petit jury is an old-fashioned name for the jury that hears a lawsuit or criminal prosecution. Petit is the French term meaning "small", to distinguish it from a "grand" jury, which performs other duties, mainly to return an indictment or not. A person on a petit jury is part of the most common type of jury service.
Following are the differences between a grand jury and a petit jury.
Grand Jury vs. Petit Jury:
A grand jury is a group of jurors who hear testimony for the prosecution’s witnesses as well as a statement about the crime from the prosecutor. A grand jury is run mostly by the prosecutor, and although the suspect does have a right to speak at a grand jury hearing, he or she can only be cross-examined by the prosecutor, and the defense attorney plays no role.
A petit jury is a group of jurors who hear testimony from both sides during a criminal trial proceeding. The petit jury’s purpose is either to convict or acquit a defendant of criminal charges.
Most grand juries contain between sixteen and twenty-three jurors, while a petit jury consists of six-to-twelve jurors. The size difference is attributable mostly to the purpose; the grand jury must indict the suspect, while the petit jury must convict or acquit. Most experts believe that if a petit jury was larger, there would be many more hung juries during criminal trials.
A grand jury is closed to the public, while a petit jury trial is open to the public. Most grand jury hearings consist only of the witnesses, the jurors and the prosecutor(s), and a petit jury trial can have as many attendees as the court room can hold.
Most petit juries consist of jurors who are selected to participate in one single trial, which often lasts less than ten days. Even high-profile cases last a few months at most, and after that, the jurors have completed their service. A grand jury, however, consists of jurors who serve for the period of a court term, which can be up to eighteen months.
In a trial overseen by a petit jury, the jurors must be unanimous in their decision to convict or acquit. If the jury is “split” one way or another, the judge will declare either a hung jury or a mistrial, and the prosecution can try the case again if the People wish. However, a grand jury does not have to be unanimous. The exact number or jurors varies from state-to-state, but in federal grand juries, the prosecution needs only twelve jurors to recommend indictment.