A rehearing is a situation in which a court agrees to hear a decided matter again. Rehearings are also sometimes known as retrials or new hearings. Such hearings are only granted in special circumstances. The ability to request a rehearing can be an important aspect of a justice system, but such hearings can also be used abusively by people who are trying to circumvent the legal system. For this reason, judges consider carefully before allowing a rehearing.
In a rehearing, the previous case is set aside and the case is heard all over again in the court before a judge and jury, if it is a case for which a jury is needed. Both sides present evidence and arguments before the court, and the matter is decided again at the conclusion of the hearing. Once a rehearing has occurred there is usually reluctance to allow yet another new hearing, so care is taken to make sure that the rehearing complies with the law and is fair to all parties.
One reason to request a rehearing is misconduct. If it can be demonstrated that one or more attorneys, the judge, or the jury engaged in misconduct, the results of the previous trial can be set aside. Likewise, if there is a clerical error which tainted the outcome of the case it may be tried again in the same court. A higher court can also order a rehearing on appeal if it finds that the lower court did not conduct the trial properly and that the outcome must be set aside so that the case can be repeated.
A legal rehearing may also be permitted if one party can show that there was important evidence which was not available. This can include evidence discovered after the trial, evidence which was not presented at the trial, or evidence which someone was unaware of. Verdicts on the basis of poor evidence and incomplete information are not deemed fair in most courts of law and they can be set aside if a judge rules that missing evidence would have been critical to the outcome of the trial.
Rehearings are expensive. Court costs can become considerable with a second hearing. For this reason, all parties involved in cases tried in court generally try to ensure that things will go smoothly and correctly on the first try. There are few advantages to needing a rehearing and thus there is an incentive to avoid this situation.