A jury is a group of people randomly selected to decide a case in the court system. Juries are used in some countries with legal systems based on English common law, including the United States, Canada, Australia and Ireland. In countries with a different legal system, a judge alone may determine guilt.
In most jurisdictions, jurors are sworn in or affirmed before sitting on a jury to be able to consider the evidence presented in the trial. This process usually happens after the judge has given an overview of the case, and before the lawyers begin their opening statements. Jurors are also provided with information cards containing minimal details about their personal and professional life, such as name, age, occupation and length of employment, number and ages of family members, and whether the person has served on a prior jury.
It is important to remember that jurors must remain impartial and not use any private source of information about the case as they consider their verdict. If a juror learns something about the case from a non-juror or from any other source, they should inform the judge as soon as possible. This is because any information a juror obtains outside the jury room may be only partly true, biased or irrelevant to the case. Moreover, if a juror talks about the case with anyone outside the jury room, they may be in contempt of court. A lawyer may challenge a juror for cause if the attorney feels that the potential juror could be partial or biased. However, the attorney must give a reason for challenging a juror or risk having their challenge dismissed as unfounded.