Free US Law Dictionary

Exclusionary Rule

The exclusionary rule is a legal principle in the United States, under constitutional law, that holds that evidence collected or analyzed in violation of the defendant's constitutional rights is inadmissible for a criminal prosecution in a court of law. This is an example of a prophylactic rule formulated by the judiciary in order to protect a constitutional right. The exclusionary rule is designed to provide a remedy and disincentive, short of criminal prosecution, for prosecutors and police who illegally gather evidence in violation of the Fourth and Fifth Amendments in the Bill of Rights, which provide for protection from unreasonable searches and seizure and compelled self-incrimination. The exclusionary rule also applies to violations of the Sixth Amendment, which guarantees the right to counsel.

The Exclusionary Rule judges the admissibility of evidence based on deontological ethics[verification needed]; that is, it is concerned with how evidence is acquired, rather than what the evidence proves.[verification needed] For this reason, in strict cases, when an illegal action is used by police/prosecution to gain any incriminating result, all evidence whose recovery stemmed from the illegal action - this evidence is known as "fruit of the poisonous tree" - can be thrown out from a jury (or be grounds for a mistrial if too much information has been irrevocably revealed).[verification needed]

The Exclusionary Rule applies to all citizens or aliens (illegal or documented) who reside within the United States.