The judge, the man or woman seated at the bench wearing a black gown (called a robe), typically does some or all of the following:
- conducts hearings and makes rulings concerning pretrial business such as preliminary hearings and motions
- determines how cases will be tried, subject to established legal rules of evidence and procedure
- makes legal rulings during trial, such as whether to admit or exclude particular evidence
- decides on the guilt or innocence of the defendant when the defendant has opted for a nonjury trial
- instructs the jury (if there is one) on the law it must follow to decide the defendant’s guilt or innocence, and
- sentences convicted defendants following a guilty verdict or negotiated plea.
Not all judges perform all these tasks. Though many do, other judges perform only some of them. For example, some judges—especially in large metropolitan areas—are assigned to hear only pretrial motions, conduct only misdemeanor trials, or handle only preliminary hearings in felony cases.
“Court,” “bench,” “magistrate,” and “commissioner” are sometimes used interchangeably with the word “judge.” For example, a trial before a judge alone without a jury may be called a “bench trial.”
Some judicial titles suggest particular functions. For example, the title “Justice” usually refers to a judge in the highest appeals court in a state or in the United States Supreme Court.
Commissioners and magistrates are typically lawyers appointed by the judges in a court system to act as judges—for example, U.S. magistrates are appointed by federal district court judges. The judges may delegate full judicial authority to magistrates and commissioners or limit them to certain types of cases or certain functions within cases. For example, a magistrate might have authority to set bail, conduct arraignments, and issue search and arrest warrants, but not to conduct trials.