Also known as: exclusionary principles · exclusionary rule
Written by attorneys · grounded in primary & secondary sources — see below
A judicially created doctrine that bars the admission of evidence obtained through violations of the Fourth Amendment in criminal proceedings. The doctrine applies to both federal and state courts and extends to derivative evidence acquired by exploiting the initial illegality.
State officers searched Enzo Eastwood's apartment without a warrant and seized documents. The prosecution offered the documents at trial in state court. The court suppressed the evidence because the officers violated the Fourth Amendment and the exclusionary principle requires inadmissibility in state proceedings.
Officers arrested Eric Espinoza under a warrant that contained a clerical error in the address. The officers had no reason to doubt the warrant's validity. The court admitted the seized evidence because the officers relied in good faith on the defective warrant.
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Police unlawfully searched Edward Everett's car and found a weapon. Prosecutors proved that routine inventory procedures would have located the weapon hours later. The court admitted the weapon under the inevitable discovery exception to the exclusionary principle.
Officers executed a search warrant on Elise Everly's home that a magistrate later found lacked probable cause. The officers had no knowledge of any defects and the warrant appeared valid on its face. The court denied suppression because the officers acted in objective good faith.
Agents unlawfully detained Emily Ellis and obtained a lead that produced a later search warrant. The resulting evidence flowed directly from the initial illegality. The court suppressed the evidence as fruit of the poisonous tree under the exclusionary principle.
Police searched a car belonging to Edith Eberhardt's passenger and found contraband. Edith had no ownership or control over the vehicle. The court denied her motion to suppress because she lacked a legitimate expectation of privacy in the searched area.
The exclusionary principle bars both evidence obtained directly through a constitutional violation and derivative evidence acquired by exploiting that illegality. Courts apply the fruit-of-the-poisonous-tree doctrine to determine whether later evidence remains tainted.
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The good-faith exception prevents suppression when officers reasonably rely on a warrant that is later found defective due to clerical errors or lack of probable cause. Suppression is still required if the officers' reliance was unreasonable or the warrant was facially deficient.
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The prosecution must demonstrate that the police would have discovered the evidence by lawful means even without the unconstitutional conduct. Routine procedures such as inventory searches can satisfy this showing when they are independent of the violation.
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A valid preexisting arrest warrant can attenuate the taint of an unlawful stop when it constitutes a significant intervening circumstance and the officer's conduct was not flagrant. Courts weigh temporal proximity, intervening events, and the purposefulness of the misconduct.
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…recently fixed as Department of Justice policy. See Beaney, Right to Counsel 29-30, 36-42 (1955). In Mapp , which imposed the exclusionary rule on the States for Fourth Amendment violations, more than half of the States had themselves already adopted some such rule. See 367 U. S., at 651. In Gideon , which extended Johnson v.…