The
exclusionary rule is a legal principle in the
United States, under
constitutional law, which holds that
evidence collected or analyzed in violation of the
defendant's
constitutional rights is sometimes
inadmissible for a
criminal prosecution in a
court of law. This may be considered an example of a
prophylactic rule formulated by the judiciary in order to protect a constitutional right. The exclusionary rule may also, in some circumstances at least, be considered to follow directly from the constitutional language, such as the
Fifth Amendment's command that no person "shall be compelled in any criminal case to be a witness against himself" and that no person "shall be deprived of life, liberty or property without due process of law".