The number of people on a jury depends on the jurisdiction of the court. The federal court system and the individual state courts determine how many jury members sit for criminal and civil cases.
In the federal courts, 12 individuals sit for criminal cases, along with an additional one to six alternate jurors. Federal civil cases convene with six to 12 jurors. Alternate jurors are not selected for civil cases.
On the state and local levels, the specific court rules govern the amount of jurors for each case. Most juries are historically comprised of 12 members, according to the American Bar Association. However, it is not uncommon to see juries with six or eight members.