A judge is an elected or appointed official who conducts court proceedings in civil disputes (usually involving money or property) and in criminal prosecutions (in which a person or entity has been charged with a crime). Judges must be impartial and strive to properly interpret the meaning and application of the law.

In criminal prosecutions (cases), when a case first comes to the court, the judge must decide whether there is enough evidence to support a reasonable belief that a crime has occurred and also that the person in question committed that crime. If the defendant cannot afford to hire a lawyer, the judge must appoint a lawyer for them. The judge also sets the amount of bail. Once the defendant has an attorney and the bail amount has been set, the defendant enters a plea of guilty or not guilty. The judge must ensure that the plea has been made voluntarily.

The role of a judge during a hearing depends on whether a jury is present. In most serious criminal cases a jury is present and is thus the trier of fact—meaning that the jury looks at the evidence presented to the court and determines what actually happened and whether the defendant is guilty. In these cases, the judge is the trier of law—meaning the judge ensures that everything happening in the courtroom follows the rules of law.

If a party in a civil or criminal case has not requested a jury, or is not entitled to a jury, the judge becomes both the trier of fact and the trier of law. This is more common in civil cases in which there is a relatively small amount of money in dispute—but in criminal cases it happens only if both the state and the defendant agree in writing not to have a jury trial.

Judges may also determine the defendant’s sentence or punishment in criminal cases, and in some civil cases, judges determine the amount of sanctions, penalties, or damages.

In Illinois, judges are responsible for overseeing court proceedings in both civil disputes and criminal prosecutions. They must remain impartial and interpret the law accurately. In criminal cases, judges initially determine if there is sufficient evidence to believe a crime has been committed and that the accused is likely responsible. If the accused cannot afford an attorney, the judge is required to appoint one. Judges also set bail and ensure that any plea entered by the defendant is voluntary. The judge's role varies depending on whether a jury is present. With a jury, the judge acts as the trier of law, ensuring legal procedures are followed, while the jury serves as the trier of fact. If there is no jury, which can occur in civil cases with smaller monetary disputes or in criminal cases by agreement, the judge assumes both roles. Additionally, judges in Illinois have the authority to sentence defendants in criminal cases and may determine sanctions or damages in civil cases.