Grand jury vs. trial jury: what's the difference?

If your summons says "grand jury," you're being asked to do something quite different from the courtroom trials most people picture. Here's how the U.S. Courts describe the two federal jury types. Many states use both too, with their own variations.

Petit (trial) jury

A petit jury is a trial jury. It decides both criminal and civil cases.

• Criminal cases: the jury decides whether the government has proved beyond a reasonable doubt that the defendant committed the crime charged.
• Civil cases: the jury decides whether the plaintiff has shown, by a preponderance of the evidence (more likely than not), that the defendant injured the plaintiff in a way that calls for compensation. The U.S. Courts note this is a much lower standard than in a criminal trial, because nobody's freedom is at stake.

Federal petit juries have 6 to 12 members. Trials are generally public, but deliberations are private. A petit juror hears one case at most and is then discharged.

Grand jury

A grand jury deals only with the early stage of criminal cases. It hears evidence presented by a prosecutor and decides whether there's "probable cause" to believe someone committed a crime and should be put on trial. If so, it issues an indictment. The federal trial jurors' handbook explains that an indictment is a written accusation by a grand jury charging the defendant with an offense.

• Size: 16 to 23 grand jurors.
• Secrecy: proceedings are private.
• Term: federal grand jurors generally serve up to 18 months, extendable to 24 months by a judge, and hear many cases over that time.
• Schedule: grand juries don't sit every day. A grand jury in a smaller district may meet one day every other week. In a busy district it may meet a couple of days each week.

Pay

Federal grand and petit jurors both earn $50 a day. The U.S. Courts say petit jurors may get up to $60 a day after 10 days if the presiding judge orders it, and grand jurors may get up to $60 a day after 45 days of service. Use the pay calculator to estimate.

Planning for grand jury service

Because grand jury service stretches over months, the scheduling questions are different. Ask the jury office for the meeting calendar as soon as possible, give it to your employer, and raise conflicts early. If the commitment would be a genuine hardship, say so when you respond. See how to postpone jury duty and jury duty and your job.

State grand juries

Not every state uses grand juries the same way. Some use them for most serious charges, others rarely. If you're summoned to a state grand jury, your state's jury page and the court's orientation will explain the term and schedule.