UNITED STATES SUPREME COURT

United States v. Leon

468 U.S. 897 (1984)

Acting on the basis of information from a confidential informant, officers of the Burbank, Cal., Police Department initiated a drug-trafficking investigation involving surveillance of respondents’ activities. Based on an affidavit summarizing the police officers’ observations, Officer Rombach prepared an application for a warrant to search three residences and respondents’ automobiles for an extensive list of items. The application was reviewed by several Deputy District Attorneys, and a facially valid search warrant was issued by a state court judge. Ensuing searches produced large quantities of drugs and other evidence. Respondents were indicted for federal drug offenses, and filed motions to suppress the evidence seized pursuant to the warrant. After an evidentiary hearing, the District Court granted the motions in part, concluding that the affidavit was insufficient to establish probable cause. Although recognizing that Officer Rombach had acted in good faith, the court rejected the Government’s suggestion that the Fourth Amendment exclusionary rule should not apply where evidence is seized in reasonable, good faith reliance on a search warrant. The Court of Appeals affirmed, also refusing the Government’s invitation to recognize a good faith exception to the rule. The Government’s petition for certiorari presented only the question whether a good faith exception to the exclusionary rule should be recognized.

Held:

1. The Fourth Amendment exclusionary rule should not be applied so as to bar the use in the prosecution’s case in chief of evidence obtained by officers acting in reasonable reliance on a search warrant issued by a detached and neutral magistrate but ultimately found to be invalid.

(a) An examination of the Fourth Amendment’s origin and purposes makes clear that the use of fruits of a past unlawful search or seizure works no new Fourth Amendment wrong. The question whether the exclusionary sanction is appropriately imposed in a particular case as a judicially created remedy to safeguard Fourth Amendment rights through its deterrent effect, must be resolved by weighing the costs and benefits of preventing the use in the prosecution’s case in chief of inherently trustworthy tangible evidence. Indiscriminate application of the exclusionary rule — impeding the criminal justice system’s truthfinding function and allowing some guilty defendants to go free — may well generate disrespect for the law and the administration of justice.

(b) Application of the exclusionary rule should continue where a Fourth Amendment violation has been substantial and deliberate, but the balancing approach that has evolved in determining whether the rule should be applied in a variety of contexts — including criminal trials — suggests that the rule should be modified to permit the introduction of evidence obtained by officers reasonably relying on a warrant issued by a detached and neutral magistrate.

(c) The deference accorded to a magistrate’s finding of probable cause for the issuance of a warrant does not preclude inquiry into the knowing or reckless falsity of the affidavit on which that determination was based, and the courts must also insist that the magistrate purport to perform his neutral and detached function and not serve merely as a rubber stamp for the police. Moreover, reviewing courts will not defer to a warrant based on an affidavit that does not provide the magistrate with a substantial basis for determining the existence of probable cause. However, the exclusionary rule is designed to deter police misconduct, rather than to punish the errors of judges and magistrates. Admitting evidence obtained pursuant to a warrant while at the same time declaring that the warrant was somehow defective will not reduce judicial officers’ professional incentives to comply with the Fourth Amendment, encourage them to repeat their mistakes, or lead to the granting of all colorable warrant requests.

(d) Even assuming that the exclusionary rule effectively deters some police misconduct and provides incentives for the law enforcement profession as a whole to conduct itself in accord with the Fourth Amendment, it cannot be expected, and should not be applied, to deter objectively reasonable law enforcement activity. In the ordinary case, an officer cannot be expected to question the magistrate’s probable cause determination or his judgment that the form of the warrant is technically sufficient. Once the warrant issues, there is literally nothing more the policeman can do in seeking to comply with the law, and penalizing the officer for the magistrate’s error, rather than his own, cannot logically contribute to the deterrence of Fourth Amendment violations.

(e) A police officer’s reliance on the magistrate’s probable cause determination and on the technical sufficiency of the warrant he issues must be objectively reasonable. Suppression remains an appropriate remedy if the magistrate or judge in issuing a warrant was misled by information in an affidavit that the affiant knew was false or would have known was false except for his reckless disregard of the truth, or if the issuing magistrate wholly abandoned his detached and neutral judicial role. Nor would an officer manifest objective good faith in relying on a warrant based on an affidavit so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable. Finally, depending on the circumstances of the particular case, a warrant may be so facially deficient — i.e., in failing to particularize the place to be searched or the things to be seized — that the executing officers cannot reasonably presume it to be valid.

2. In view of the modification of the exclusionary rule, the Court of Appeals’ judgment cannot stand in this case. Only respondent Leon contended that no reasonably well trained police officer could have believed that there existed probable cause to search his house. However, the record establishes that the police officers’ reliance on the state court judge’s determination of probable cause was objectively reasonable.

701 F.2d 187, reversed.