The Constitution guarantees a right to a trial by a jury of our peers in serious criminal prosecutions. The jury is charged with finding the facts of the case after carefully reviewing the evidence and deliberating. But how, then, are jurors selected?
Jury selection happens in two parts. The first part is, essentially, random selection. The state or federal district will randomly pull names off of lists that the state keeps in the regular course of business. These lists could include a list of registered voters, a list of people who hold driver's licenses, or a list of people receiving unemployment benefits.
Once your name is pulled from one of these lists, you will receive a notice in the mail informing you of the date you have to go to court. The rules can vary by state, but unless you have some pressing reason to miss the first day of jury service, you generally have to go.
"Voir Dire" refers to the second stage of jury procedures, and is the process by which the court and the attorneys narrow down the pool of juries to the 12 people that will decide the case. The process for voir dire varies from state to state, and even from judge to judge. Sometimes, if the juror pool is too large, the judge will randomly pick some people and excuse them from duty.
Normally, however, the judge and attorneys will interview each juror about their backgrounds and beliefs. Sometimes this happens in front of the rest of the jury pool, sometimes this happens in private. Each attorney has the chance to object to jurors. There are two types of objections: "peremptory challenges" and "challenges for cause." When an attorney challenges a juror for cause, there was most likely something in the juror's background that would prejudice them in the case. For example, it is likely that an attorney would not allow a retired police officer to sit on a jury that decides a police brutality case. In federal courts, each side has an unlimited number of challenges for cause. Attorneys do not need to give reasons for peremptory challenges, but each side only gets a limited number of these types of challenges. Of course, an attorney is not allowed to use peremptory challenges based on the race or gender of potential jurors.
For more information, see FindLaw's section on Litigation.