What is Exclusionary Rule?

Alternative Forms: Exclusionary rules
Legal Definition
In the United States, the exclusionary rule is a legal rule, based on constitutional law, saying 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".

"The exclusionary rule is grounded in the Fourth Amendment and it is intended to protect citizens from illegal searches and seizures." The exclusionary rule is also designed to provide a remedy and disincentive, which is short of criminal prosecution in response to prosecutors and police who illegally gather evidence in violation of the Fifth Amendment in the Bill of Rights compelled to self-incrimination. The exclusionary rule also protects against violations of the Sixth Amendment, which guarantees the right to counsel.

Most states also have their own exclusionary remedies for illegally obtained evidence under their state constitutions and/or statutes, some of which predate the federal constitutional guarantees against unlawful searches and seizures and compelled self-incrimination.

This rule is occasionally referred to as a legal technicality because it allows defendants a defense that does not address whether the crime was actually committed. In this respect, it is similar to the explicit rule in the Fifth Amendment protecting people from double jeopardy. 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).

The exclusionary rule applies to all persons within the United States regardless of whether they are citizens, immigrants (legal or illegal), or visitors.
-- Wikipedia
Legal Definition
The exclusionary rule prevents the government from using most evidence gathered in violation of the United States Constitution. The exclusionary rule applies to evidence gained from an unreasonable search or seizure in violation of the Fourth Amendment, see Mapp v. Ohio, 367 U.S. 643 (1961), to improperly elicited self-incriminatory statements gathered in violation of the Fifth Amendment, see Miranda v. Arizona, 384 U.S. 439 (1966), and to evidence gained in situations where the government violated defendants’ Sixth Amendment right to counsel, see Miranda. The rule does not apply in civil cases, including deportation hearings. See INS v. Lopez-Mendoza, 468 U.S. 1032.

If evidence that falls within the scope of the exclusionary rule led law enforcement to other evidence, which they would not otherwise have located, then the exclusionary rule applies to the related evidence found subsequent to the excluded evidence, subject to a few exceptions. Such subsequent evidence is called “fruit of the poisonous tree.”

The exclusionary rule is a court-created remedy and deterrent, not an independent constitutional right. The purpose of this rule is to deter law enforcement officers from conducting searches or seizures in violation of the Fourth Amendment and provide remedies to defendants whose rights have been infringed upon. Courts have also carved out several exceptions to the exclusionary rule where the costs of exclusion outweigh its deterrent or remedial benefits. Thus, the rule is not triggered when courthouse errors lead police officers to mistakenly believe that they have a valid search warrant, because excluding the evidence would not deter police officers from violating the law in the future.


Under the search or seizure.


In cases where the relationship between the evidence challenged and the unlawful search or seizure is too remote and attenuated, the evidence may be purged and be admissible.


The exclusionary rule does not prevent the government from introducing illegally gathered evidence to “impeach,” or attack the credibility of, defendants’ testimony at trial. The Supreme Court recognized this exception to prevent perjury. Even when the government suspects perjury, however, it may only use tainted evidence for impeachment, and may not use it to show guilt.


Due to qualified immunity, the exclusionary rule is often defendants’ only remedy when police officers conduct an unreasonable search or violate their Miranda rights. Even if officers violate a defendant's constitutional or statutory rights, qualified immunity protects them from a lawsuit unless no reasonable officer would believe that their conduct was legal.
Legal Definition
a doctrine that will prevent the illegally gathered evidence being presented to the court.
Legal Definition
Proof and facts must be proven solely by legal, moral methods. Rules of evidence. t