Types of Juries

Petit Jury 

Petit juries, also known as trial juries, decide both criminal and civil cases. In a criminal case, a petit jury decides whether the Government has proved beyond a reasonable doubt that the defendant committed the crime as charged. In a civil case, a petit jury decides whether the plaintiff establishes with evidence that is more likely than not, known in legal terms as preponderance of the evidence, that the defendant injured the plaintiff in some way that requires appropriate compensation. This is a much lower standard of proof than in a criminal trial since no party’s freedom is at issue in a civil matter.  

 Learn about the types of cases heard in federal courts. 

• Petit juries are comprised of 6-12 people. 
• Trials are generally public, but jury deliberations are private. 
• Petit juries render a verdict, of guilty/not guilty in a criminal case, or in favor of a defendant or plaintiff in a civil case. 
• Petit jurors hear a maximum of one case and are then discharged. 

Read the Petit Jury Handbook (PDF) for more information.  

Grand Jury 

A grand jury focuses on preliminary criminal matters only and assesses evidence presented by a prosecutor to determine whether there is “probable cause” to believe an individual committed a crime and should be put on trial. If the grand jury determines there is enough evidence, an indictment will be issued against the individual. 

• Consists of 16-23 grand jurors. 
• Proceedings are private. 
• Grand jurors generally serve up to 18 months, but can serve for up to 24 months, if an extension is granted by a judge.   
• Grand jurors consider multiple cases over the course of their term of service.  

Unlike petit juries, grand juries do not meet every day, instead meeting in any number of calendar combinations throughout their term. For instance, a grand jury in a smaller district may meet only one day every other week, while a grand jury in a large district with significant criminal investigations may meet for a couple of days each week over the course of the term. 

Read the Grand Juror Handbook (PDF) for more information.