Trial, method of settling disagreements of determining criminal guilt. In the United states, this involves a hearing before a judge, with or without a jury. In the United States the right of an accused person to a speedy and public trial by a jury of peers is guaranteed in the Constitution. Trials in common law countries, such as the United Kingdom and United States, are “adversary” proceedings, in which the court impartially decides between the evidence of two parties. Under civil law systems trials tend to be more “inquisitorial,” allowing the court itself a greater role in the gathering of evidence. Under both systems the judge ensures that procedure is followed and that the rules of evidence are observed, and determines the guilty offender's sentence. Questions of fact are left to a jury, if there is one; jury trial is more expensive and time-consuming, and so it is reserved for more serious offenses.