exclusionary rule n
any of various rules that exclude or suppress evidence
: 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 in the Important Cases section NOTE: The U.S. Supreme Court established the rule that evidence gathered by a governmental agent in violation of esp. 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.
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.