Criminal Law: Grand Jury Vs. Petit Jury

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.

Following are the differences between a grand jury and a petit jury.

Grand Jury vs. Petit Jury: Purpose

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.

Grand Jury vs. Petit Jury: Size

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.

Grand Jury vs. Petit Jury: Attendance

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.

Grand Jury vs. Petit Jury: Juror Service

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.

Grand Jury vs. Petit Jury: Agreement

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.