Double jeopary is a procedural defense (and, in many countries such as the United States, Canada, Mexico and India, a constitutional right) that forbids that a defendant be tried twice for the same crime on the same set of facts. At common law a defendant may plead autrefois acquit or autrefois convict (a peremptory plea); meaning the defendant has been acquitted or convicted of the same offense. If this issue is raised, evidence will be placed before the court, which will normally rule as a preliminary matter whether the plea is substantiated, and if it so finds, the projected trial will be prevented from proceeding.