A trier of fact is the person or group of persons in a trial who make findings of fact as opposed to rulings of law. In legal parlance, a trial is an event in which parties to a dispute present information (in the form of evidence) in a formal setting, usually a court, before a judge, jury, or other designated finder of fact, in order to achieve a resolution to their dispute. ... A finding of fact is a determination on the evidence regarding a issue of fact raised by one party to case made by the fact finder, usually a judge or a jury. ... Law (from the late Old English lagu of probable North Germanic origin) in politics and jurisprudence, is a set of rules or norms of conduct which mandate, proscribe or permit specified relationships among people and organizations, intended to provide methods for ensuring the impartial treatment of such people, and provide...

In a jury trial, the jury is the trier of fact. The jury finds the facts and applies them to the law it is instructed by the judge to use in order to reach its verdict. Thus, in a jury trial, the findings of fact are made by the jury while the judge makes legal rulings as to what evidence will be heard by the jury and what the law will be that governs the case. The jury is supposed to strictly follow the law as given by the judge, but it does not always do so. In some cases this amounts to jury nullification, i.e. the jury effectively re-writing the law or blatantly ignoring it in a particular case. A jury is a sworn body of persons convened to render a rational, impartial verdict and a finding of fact on a legal question officially submitted to them, or to set a penalty or judgment in a jury trial of a court of law. ... A judge or justice is an official who presides over a court. ... Jury nullification is a jurys refusal to render a verdict according to the law, as instructed by the court, regardless of the weight of evidence presented. ...

In a "bench trial," or non-jury trial, a judge is the trier of fact. In a bench trial, the judge makes both findings of fact and rulings of law. A bench trial in the U.S. is a trial before a judge in which the defendant has waived his/her right to a jury trial. ...

In Anglo-american based legal systems, there is a strong reluctance to change findings of fact made by a jury. This principle is enshrined in the Seventh Amendment to the United States Constitution, which provides that "...no fact tried by a jury, shall be otherwise re-examined in any Court of the United States, than according to the rules of the common law." Amendment VII (the Seventh Amendment) of the United States Constitution, which is part of the Bill of Rights, codifies the right to jury trial in certain civil trials. ...