The Jury Selection and Service Act establishes the process for selecting jurors and it outlines qualifications a person must meet to serve on a federal jury.
There are two types of juries serving distinct functions in the federal trial courts: trial juries (also known as petit juries), and grand juries.
Selection of Jurors
Potential jurors are chosen from a jury pool generated by random selection of citizens' names from lists of registered voters, or combined lists of voters and people with drivers licenses, in the judicial district. The potential jurors complete questionnaires to help determine whether they are qualified to serve on a jury. After reviewing the questionnaires, the court randomly selects individuals to be summoned to appear for jury duty. These selection methods help ensure that jurors represent a cross section of the community, without regard to race, gender, national origin, age or political affiliation.
Being summoned for jury service does not guarantee that an individual actually will serve on a jury. When a jury is needed for a trial, the group of qualified jurors is taken to the courtroom where the trial will take place. The judge and the attorneys then ask the potential jurors questions to determine their suitability to serve on the jury, a process called voir dire. The purpose of voir dire is to exclude from the jury people who may not be able to decide the case fairly. Members of the panel who know any person involved in the case, who have information about the case, or who may have strong prejudices about the people or issues involved in the case, typically will be excused by the judge. The attorneys also may exclude a certain number of jurors without giving a reason.
Petit (Trial) Jury
A civil petit jury is typically made up of 6 to 12 persons. In a civil case, the role of the jury is to listen to the evidence presented at a trial, to decide whether the defendant injured the plaintiff or otherwise failed to fulfill a legal duty to the plaintiff, and to determine what the compensation or penalty should be. A criminal petit jury is usually made up of 12 members. Criminal juries decide whether the defendant committed the crime as charged. The sentence usually is set by a judge. Verdicts in both civil and criminal cases must be unanimous, although the parties in a civil case may agree to a non-unanimous verdict. A jury's deliberations are conducted in private, out of sight and hearing of the judge, litigants, witnesses, and others in the courtroom.
A grand jury, which normally consists of 16 to 23 members, has a more specialized function. The United States attorney, the prosecutor in federal criminal cases, presents evidence to the grand jury for them to determine whether there is "probable cause" to believe that an individual has committed a crime and should be put on trial. If the grand jury decides there is enough evidence, it will issue an indictment against the defendant. Grand jury proceedings are not open for public observation.