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 Indiana, judges are either elected or appointed to oversee court proceedings in both civil disputes and criminal prosecutions. Their primary role is to ensure impartiality and the correct application of the law. In criminal cases, Indiana judges assess the evidence to determine if there is probable cause to believe a crime has been committed and that the accused is responsible. If the defendant cannot afford an attorney, the judge is responsible for appointing one. Judges also set bail and ensure that any plea entered by the defendant is made voluntarily. During trials, the presence of a jury dictates the judge's role: with a jury, the judge focuses on the application of law, while the jury determines the facts. If there is no jury, the judge assumes both roles. In Indiana, criminal defendants can waive their right to a jury trial if both the state and the defendant consent in writing. Judges are also tasked with sentencing in criminal cases and may determine penalties in civil cases. The specifics of these roles and procedures are governed by Indiana state statutes and federal law, which outline the detailed responsibilities and powers of judges in the state's judicial system.