exclusionary rule

noun

1. : any of various rules that exclude or suppress evidence; specifically : a rule of evidence that excludes or suppresses evidence obtained in violation of a defendant's constitutional rights — see also fruit of the poisonous tree, good faith exception, Mapp v. Ohio and Wong Sun v. United States : a rule of evidence that excludes or suppresses evidence obtained in violation of a defendant's constitutional rights — see also fruit of the poisonous tree, good faith exception, Mapp v. Ohio and Wong Sun v. United States

   Note: The U.S. Supreme Court established the rule that evidence gathered by a governmental agent in violation of especially the Fourth and Fifth Amendments to the U.S. Constitution cannot be admitted against a defendant. The rule is available primarily in criminal trials or quasi-criminal proceedings (as punitive administrative hearings) and must also be observed by state courts. There are various statutory exclusionary rules in addition to the rule established by the Supreme Court.