Illinois v. Gates, 462 U.S. 213 (1983)
On May 3, 1978, the Police Department of Bloomingdale, Ill., received an anonymous letter which included statements that respondents, husband and wife, were engaged in selling drugs; that the wife would drive their car to Florida on May 3 to be loaded with drugs, and the husband would fly down in a few days to drive the car back; that the car’s trunk would be loaded with drugs; and that respondents presently had over $100,000 worth of drugs in their basement. Acting on the tip, a police officer determined respondents’ address and learned that the husband made a reservation on a May 5 flight to Florida. Arrangements for surveillance of the flight were made with an agent of the Drug Enforcement Administration (DEA), and the surveillance disclosed that the husband took the flight, stayed overnight in a motel room registered in the wife’s name, and left the following morning with a woman in a car bearing an Illinois license plate issued to the husband, heading north on an interstate highway used by travelers to the Bloomingdale area. A search warrant for respondents’ residence and automobile was then obtained from an Illinois state court judge, based on the Bloomingdale police officer’s affidavit setting forth the foregoing facts and a copy of the anonymous letter. When respondents arrived at their home, the police were waiting, and discovered marihuana and other contraband in respondents’ car trunk and home. Prior to respondents’ trial on charges of violating state drug laws, the trial court ordered suppression of all the items seized, and the Illinois Appellate Court affirmed. The Illinois Supreme Court also affirmed, holding that the letter and affidavit were inadequate to sustain a determination of probable cause for issuance of the search warrant under Aguilar v. Texas, 378 U. S. 108, and Spinelli v. United States, 393 U. S. 410, since they failed to satisfy the “two-pronged test” of (1) revealing the informant’s “basis of knowledge” and (2) providing sufficient facts to establish either the informant’s “veracity” or the “reliability” of the informant’s report.
1. The question — which this Court requested the parties to address — whether the rule requiring the exclusion at a criminal trial of evidence obtained in violation of the Fourth Amendment should be modified so as, for example, not to require exclusion of evidence obtained in the reasonable
belief that the search and seizure at issue was consistent with the Fourth Amendment, will not be decided in this case, since it was not presented to or decided by the Illinois courts. Although prior decisions interpreting the “not pressed or passed on below” rule have not involved a State’s failure to raise a defense to a federal right or remedy asserted below, the purposes underlying the rule are, for the most part, as applicable in such a case as in one where a party fails to assert a federal right. The fact that the Illinois courts affirmatively applied the federal exclusionary rule does not affect the application of the “not pressed or passed on below” rule. Nor does the State’s repeated opposition to respondents’ substantive Fourth Amendment claims suffice to have raised the separate question whether the exclusionary rule should be modified. The extent of the continued vitality of the rule is an issue of unusual significance, and adhering scrupulously to the customary limitations on this Court’s discretion promotes respect for its adjudicatory process and the stability of its decisions, and lessens the threat of untoward practical ramifications not foreseen at the time of decision. Pp. 462 U. S. 217-224.
2. The rigid “two-pronged test” under Aguilar and Spinelli for determining whether an informant’s tip establishes probable cause for issuance of a warrant is abandoned, and the “totality of the circumstances” approach that traditionally has informed probable cause determinations is substituted in its place. The elements under the “two-pronged test” concerning the informant’s “veracity,” “reliability,” and “basis of knowledge” should be understood simply as closely intertwined issues that may usefully illuminate the common sense, practical question whether there is “probable cause” to believe that contraband or evidence is located in a particular place. The task of the issuing magistrate is simply to make a practical, common sense decision whether, given all the circumstances set forth in the affidavit before him, there is a fair probability that contraband or evidence of a crime will be found in a particular place. And the duty of a reviewing court is simply to ensure that the magistrate had a substantial basis for concluding that probable cause existed. This flexible, easily applied standard will better achieve the accommodation of public and private interests that the Fourth Amendment requires than does the approach that has developed from Aguilar and Spinelli. Pp. 462 U. S. 230-241.
3. The judge issuing the warrant had a substantial basis for concluding that probable cause to search respondents’ home and car existed. Under the “totality of the circumstances” analysis, corroboration of details of an informant’s tip by independent police work is of significant value. Cf. Draper v. United States, 358 U. S. 307. Here, even standing alone, the facts obtained through the independent investigation of the Bloomingdale police officer and the DEA at least suggested that
Page 462 U. S. 215
respondents were involved in drug trafficking. In addition, the judge could rely on the anonymous letter, which had been corroborated in major part by the police officer’s efforts. Pp. 462 U. S. 241-246.
85 Ill. 2d 376, 423 N.E.2d 887, reversed.
REHNQUIST, J., delivered the opinion of the Court, in which BURGER, C.J., and BLACKMUN, POWELL, and O’CONNOR, JJ., joined. WHITE, J., filed an opinion concurring in the judgment, post, p. 462 U. S. 246. BRENNAN, J., filed a dissenting opinion, in which MARSHALL, J., joined, post, p. 462 U. S. 274. STEVENS, J., filed a dissenting opinion, in which BRENNAN, J., joined, post, p. 462 U. S. 291.
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