A kangaroo court is a judicial tribunal or assembly that ignores recognized standards of law or justice, and often carries little or no official standing in the territory within which it resides. The term may also apply to a court held by a legitimate judicial authority who intentionally disregards the court's legal or ethical obligations.
Prejudicial bias of the decision-maker or from political decree are among the most publicized causes of kangaroo courts. Such proceedings are often held to give the appearance of a fair and just trial, even though the verdict has in reality already been decided before the trial has begun. An example is the trial of Pol Pot and his brother Ieng San by the People's Revolutionary Tribunal in Cambodia in August 1979. After a lengthy trial with a duration of five days, both were convicted of death in absentia on August 19, 1979. Conclusive evidence suggests that the verdicts and the sentencing papers had been prepared in advance of the trial. Relying on this evidence the United Nations proceeded to delegitimize the tribunal stating that it did not comply with standards of international law.
A kangaroo court could also develop when the structure and operation of the forum result in an inferior brand of adjudication. A common example of this is when institutional disputants ("repeat players") have excessive and unfair structural advantages over individual disputants ("one-shot players").
Although the term kangaroo court has been erroneously explained to have its origin from Australia's courts while it was a penal colony, the first published instance is from an American source in the year 1853. Some sources suggest that it may have been popularized during the California Gold Rush of 1849, along with mustang court, as a description of the hastily carried-out proceedings used to deal with the issue of claim jumping miners. Ostensibly the term comes from the notion of justice proceeding "by leaps", like a kangaroo – in other words, "jumping over" (intentionally ignoring) evidence that would be in favour of the defendant. Another possibility is that the phrase could refer to the pouch of a kangaroo, meaning the court is in someone's pocket. The phrase is popular in the UK, US, Australia and New Zealand and is still in common use. Also note the existence of the phrase "Jumping to conclusions".