Judicial officers who assist U.S. district court judges in getting cases ready for trial. They may decide some criminal and civil trials when both parties agree to have the case heard by a magistrate judge instead of a district court judge.
Usually a petty offense, a less serious crime than a felony, punishable by less than a year of confinement.
An invalid trial caused by fundamental error. When a mistrial is declared, the trial must start again, beginning with the selection of a new jury.
Attempt to have a limited issue heard by the court. Motions can be filed before, during, and after trial.