Respondents Lance and Susan Gates were indicted for violation of state drug laws after police officers, executing a search warrant, discovered marihuana and other contraband in their automobile and home. Prior to trial the Gateses moved to suppress evidence seized during this search. The Illinois Supreme Court affirmed the decisions of lower state courts granting the motion. 85 Ill.2d 376, 423 N.E.2d 887 (1981). It held that the affidavit submitted in support of the State's application for a warrant to search the Gateses' property
We granted certiorari to consider the application of the Fourth Amendment to a magistrate's issuance of a search warrant on the basis of a partially corroborated anonymous informant's tip. 454 U.S. 1140 (1982). After receiving briefs and hearing oral argument on this question, however, we requested the parties to address an additional question:
We decide today, with apologies to all, that the issue we framed for the parties was not presented to the Illinois courts and, accordingly, do not address it. Rather, we consider the question originally presented in the petition for certiorari, and conclude that the Illinois Supreme Court read the requirements of our Fourth Amendment decisions too restrictively. Initially, however, we set forth our reasons for not addressing the question regarding modification of the exclusionary rule framed in our order of November 29, 1982. Ibid.
Our certiorari jurisdiction over decisions from state courts derives from 28 U. S. C. § 1257, which provides that "[f]inal judgments or decrees rendered by the highest court of a State in which a decision could be had, may be reviewed by the Supreme Court as follows: . . . (3) By writ of certiorari,. . . where any title, right, privilege or immunity is specially set up or claimed under the constitution, treaties or statutes
Although we have spoken frequently on the meaning of § 1257 and its predecessors, our decisions are in some respects not entirely clear. We held early on that § 25 of the Judiciary Act of 1789 furnished us with no jurisdiction unless a federal question had been both raised and decided in the state court below. As Justice Story wrote in Crowell v. Randell, 10 Pet. 368, 392 (1836); "If both of these requirements do not appear on the record, the appellate jurisdiction fails." See also Owings v. Norwood's Lessee, 5 Cranch 344 (1809).
More recently, in McGoldrick v. Compagnie Generale Transatlantique, 309 U.S. 430, 434-435 (1940), the Court observed:
Finally, the Court seemed to reaffirm the jurisdictional character of the rule against our deciding claims "not pressed nor passed upon" in state court in State Farm Mutual Automobile Ins. Co. v. Duel, 324 U.S. 154, 160 (1945), where we explained that "[s]ince the [State] Supreme Court did not pass on the question, we may not do so." See also Hill v. California, 401 U.S. 797, 805-806 (1971).
Notwithstanding these decisions, however, several of our more recent cases have treated the so-called "not pressed or passed upon below" rule as merely a prudential restriction. In Terminiello v. Chicago, 337 U.S. 1 (1949), the Court reversed a state criminal conviction on a ground not urged in state court, nor even in this Court. Likewise, in Vachon v. New Hampshire, 414 U.S. 478 (1974), the Court summarily reversed a state criminal conviction on the ground, not raised in state court, or here, that it had been obtained in violation of the Due Process Clause of the Fourteenth Amendment. The Court indicated in a footnote, id., at 479, n. 3, that it possessed discretion to ignore the failure to raise in state court the question on which it decided the case.
In addition to this lack of clarity as to the character of the "not pressed or passed upon below" rule, we have recognized that it often may be unclear whether the particular federal question presented in this Court was raised or passed upon below. In Dewey v. Des Moines, 173 U.S. 193, 197-198 (1899), the fullest treatment of the subject, the Court said
The application of these principles in the instant case is not entirely straightforward. It is clear in this case that respondents expressly raised, at every level of the Illinois judicial system, the claim that the Fourth Amendment had been violated by the actions of the Illinois police and that the evidence seized by the officers should be excluded from their trial. It also is clear that the State challenged, at every level of the Illinois court system, respondents' claim that the substantive requirements of the Fourth Amendment had been violated. The State never, however, raised or addressed the question whether the federal exclusionary rule should be modified in any respect, and none of the opinions of the
The case, of course, is before us on the State's petition for a writ of certiorari. Since the Act of Dec. 23, 1914, ch. 2, 38 Stat. 790, jurisdiction has been vested in this Court to review state-court decisions even when a claimed federal right has been upheld. Our prior decisions interpreting the "not pressed or passed on below" rule have not, however, involved a State's failure to raise a defense to a federal right or remedy asserted below. As explained below, however, we can see no reason to treat the State's failure to have challenged an asserted federal claim differently from the failure of the proponent of a federal claim to have raised that claim.
We have identified several purposes underlying the "not pressed or passed upon" rule: for the most part, these are as applicable to the State's failure to have opposed the assertion of a particular federal right, as to a party's failure to have asserted the claim. First, "[q]uestions not raised below are those on which the record is very likely to be inadequate since it certainly was not complied with those questions in mind." Cardinale v. Louisiana, 394 U.S. 437, 439 (1969). Exactly the same difficulty exists when the State urges modification of an existing constitutional right or accompanying remedy. Here, for example, the record contains little, if anything, regarding the subjective good faith of the police officers that searched the Gateses' property — which might well be an important consideration in determining whether to fashion a good-faith exception to the exclusionary rule. Our consideration of whether to modify the exclusionary rule plainly would benefit from a record containing such facts.
Likewise, "due regard for the appropriate relationship of this court to state courts," McGoldrick v. Compagnie Generale Transatlantique, 309 U. S., at 434-435, demands that those courts be given an opportunity to consider the constitutionality of the actions of state officials, and, equally important, proposed changes in existing remedies for unconstitutional
The fact that the Illinois courts affirmatively applied the federal exclusionary rule — suppressing evidence against respondents — does not affect our conclusion. In Morrison v. Watson, 154 U.S. 111 (1894), the Court was asked to consider whether a state statute impaired the plaintiff in error's contract with the defendant in error. It declined to hear the case because the question presented here had not been pressed or passed on below. The Court acknowledged that the lower court's opinion had restated the conclusion, set forth in an earlier decision of that court, that the state statute did not impermissibly impair contractual obligations. Nonetheless, it held that there was no showing that "there was any real contest at any stage of this case upon the point," id., at 115, and that without such a contest, the routine restatement
Likewise, we do not believe that the State's repeated opposition to respondents' substantive Fourth Amendment claims suffices to have raised the question whether the exclusionary rule should be modified. The exclusionary rule is "a judicially created remedy designed to safeguard Fourth Amendment rights generally" and not "a personal constitutional right of the party aggrieved." United States v. Calandra, 414 U.S. 338, 348 (1974). The question whether the exclusionary rule's remedy is appropriate in a particular context has long been regarded as an issue separate from the question whether the Fourth Amendment rights of the party seeking to invoke the rule were violated by police conduct. See, e. g., United States v. Havens, 446 U.S. 620 (1980); United States v. Ceccolini, 435 U.S. 268 (1978); United States v. Calandra, supra; Stone v. Powell, 428 U.S. 465 (1976). Because of this distinction, we cannot say that modification or abolition of the exclusionary rule is "so connected with [the substantive Fourth Amendment right at issue] as to form but another ground or reason for alleging the invalidity" of the judgment. Dewey v. Des Moines, 173 U. S., at 197-198. Rather, the rule's modification was, for purposes of the "not pressed or passed upon below" rule, a separate claim that had to be specifically presented to the state courts.
We now turn to the question presented in the State's original petition for certiorari, which requires us to decide whether respondents' rights under the Fourth and Fourteenth Amendments were violated by the search of their car and house. A chronological statement of events usefully introduces the issues at stake. Bloomingdale, Ill., is a suburb of Chicago located in Du Page County. On May 3, 1978, the Bloomingdale Police Department received by mail an anonymous handwritten letter which read as follows:
The letter was referred by the Chief of Police of the Bloomingdale Police Department to Detective Mader, who decided to pursue the tip. Mader learned, from the office of the Illinois Secretary of State, that an Illinois driver's license had
Mader then made arrangements with an agent of the Drug Enforcement Administration for surveillance of the May 5 Eastern Airlines flight. The agent later reported to Mader that Gates had boarded the flight, and that federal agents in Florida had observed him arrive in West Palm Beach and take a taxi to the nearby Holiday Inn. They also reported that Gates went to a room registered to one Susan Gates and that, at 7 o'clock the next morning, Gates and an unidentified woman left the motel in a Mercury bearing Illinois license plates and drove northbound on an interstate highway frequently used by travelers to the Chicago area. In addition, the DEA agent informed Mader that the license plate number on the Mercury was registered to a Hornet station wagon owned by Gates. The agent also advised Mader that the driving time between West Palm Beach and Bloomingdale was approximately 22 to 24 hours.
Mader signed an affidavit setting forth the foregoing facts, and submitted it to a judge of the Circuit Court of Du Page County, together with a copy of the anonymous letter. The judge of that court thereupon issued a search warrant for the Gateses' residence and for their automobile. The judge, in deciding to issue the warrant, could have determined that the modus operandi of the Gateses had been substantially corroborated. As the anonymous letter predicted, Lance Gates had flown from Chicago to West Palm Beach late in the afternoon of May 5th, had checked into a hotel room registered in the name of his wife, and, at 7 o'clock the following morning, had headed north, accompanied by an unidentified woman,
At 5:15 a. m. on March 7, only 36 hours after he had flown out of Chicago, Lance Gates, and his wife, returned to their home in Bloomingdale, driving the car in which they had left West Palm Beach some 22 hours earlier. The Bloomingdale police were awaiting them, searched the truck of the Mercury, and uncovered approximately 350 pounds of marihuana. A search of the Gateses' home revealed marihuana, weapons, and other contraband. The Illinois Circuit court ordered suppression of all these items, on the ground that the affidavit submitted to the Circuit Judge failed to support the necessary determination of probable cause to believe that the Gateses' automobile and home contained the contraband in question. This decision was affirmed in turn by the Illinois Appellate Court, 82 Ill.App.3d 749, 403 N.E.2d 77 (1980), and by a divided vote of the Supreme court of Illinois. 85 Ill.2d 376, 423 N.E.2d 887 (1981).
The Illinois Supreme Court concluded — and we are inclined to agree — that, standing alone, the anonymous letter sent to the Bloomingdale Police Department would not provide the basis for a magistrate's determination that there was probable cause to believe contraband would be found in the Gateses' car and home. The letter provides virtually nothing from which one might conclude that its author is either honest or his information reliable; likewise, the letter gives absolutely no indication of the basis for the writer's predictions regarding the Gateses' criminal activities. Something more was required, then, before a magistrate could conclude that there was probable cause to believe that contraband would be found in the Gateses' home and car. See Aguilar v. Texas, 378 U. S., at 109, n. 1; Nathanson v. United States, 290 U.S. 41 (1933).
The Illinois Supreme Court also properly recognized that Detective Mader's affidavit might be capable of supplementing
The Illinois court, alluding to an elaborate set of legal rules that have developed among various lower courts to enforce the "two-pronged test,"
We agree with the Illinois Supreme Court that an informant's "veracity," "reliability," and "basis of knowledge" are all highly relevant in determining the value of his report. We do not agree, however, that these elements should be understood as entirely separate and independent requirements to be rigidly exacted in every case,
This totality-of-the-circumstances approach is far more consistent with our prior treatment of probable cause
As these comments illustrate, probable cause is a fluid concept — turning on the assessment of probabilities in particular factual contexts — not readily, or even usefully, reduced to a neat set of legal rules. Informants' tips doubtless come in many shapes and sizes from many different types of persons. As we said in Adams v. Williams, 407 U.S. 143, 147 (1972): "Informants' tips, like all other clues and evidence coming to a policeman on the scene, may vary greatly in their value and reliability." Rigid legal rules are ill-suited to an area of such diversity. "One simple rule will not cover every situation." Ibid.
If, for example, a particular informant is known for the unusual reliability of his predictions of certain types of criminal activities in a locality, his failure, in a particular case, to thoroughly set forth the basis of his knowledge surely should not serve as an absolute bar to a finding of probable cause based on his tip. See United States v. Sellers, 483 F.2d 37 (CA5 1973).
As early as Locke v. United States, 7 Cranch 339, 348 (1813), Chief Justice Marshall observed, in a closely related context: "[T]he term `probable cause,' according to its usual acceptation, means less than evidence which would justify condemnation . . . . It imports a seizure made under circumstances which warrant suspicion." More recently, we said that "the quanta . . . of proof" appropriate in ordinary judicial proceedings are inapplicable to the decision to issue a warrant. Brinegar, 338 U. S., at 173. Finely tuned standards such as proof beyond a reasonable doubt or by a preponderance of the evidence, useful in formal trials, have no place in the magistrate's decision. While an effort to fix some general, numerically precise degree of certainty corresponding to "probable cause" may not be helpful, it is clear that "only the probability, and not a prima facie showing, of criminal activity is the standard of probable cause." Spinelli, 393 U. S., at 419. See Model Code of Pre-Arraignment Procedure § 210.1(7) (Prop. Off. Draft 1972); 1 W. LaFave, Search and Seizure § 3.2(e) (1978).
We also have recognized that affidavits "are normally drafted by nonlawyers in the midst and haste of a criminal investigation. Technical requirements of elaborate specificity once enacted under common law pleadings have no proper place in this area." United States v. Ventresca, 380 U.S. 102, 108 (1965). Likewise, search and arrest warrants long have been issued by persons who are neither lawyers nor judges, and who certainly do not remain abreast of each judicial refinement of the nature of "probable cause." See Shadwick v. City of Tampa, 407 U.S. 345, 348-350 (1972). The rigorous inquiry into the Spinelli prongs and the complex superstructure of evidentiary and analytical rules that some have seen implicit in our Spinelli decision, cannot be reconciled with the fact that many warrants are — quite properly, 407 U. S., at 348-350 — issued on the basis of nontechnical,
Similarly, we have repeatedly said that after-the-fact scrutiny by courts of the sufficiency of an affidavit should not take the form of de novo review. A magistrate's "determination of probable cause should be paid great deference by reviewing courts." Spinelli, supra, at 419. "A grudging or negative attitude by reviewing courts toward warrants," Ventresca, 380 U. S., at 108, is inconsistent with the Fourth Amendment's strong preference for searches conducted pursuant to a warrant; "courts should not invalidate warrant[s] by interpreting affidavit[s] in a hypertechnical, rather than a commonsense, manner." Id., at 109.
If the affidavits submitted by police officers are subjected to the type of scrutiny some courts have deemed appropriate, police might well resort to warrantless searches, with the hope of relying on consent or some other exception to the Warrant Clause that might develop at the time of the search. In addition, the possession of a warrant by officers conducting an arrest or search greatly reduces the perception of unlawful or intrusive police conduct, by assuring "the individual whose property is searched or seized of the lawful authority of the executing officer, his need to search, and the limits of his power to search." United States v. Chadwick, 433 U.S. 1, 9 (1977). Reflecting this preference for the warrant process, the traditional standard for review of an issuing magistrate's probable-cause determination has been that so long as the magistrate had a "substantial basis for . . . conclud[ing]" that a search would uncover evidence of wrongdoing, the Fourth Amendment requires no more. Jones v. United States, 362 U.S. 257, 271 (1960). See United States v.
Finally, the direction taken by decisions following Spinelli poorly serves "[t]he most basic function of any government": "to provide for the security of the individual and of his property." Miranda v. Arizona, 384 U.S. 436, 539 (1966) (WHITE, J., dissenting). The strictures that inevitably accompany the "two-pronged test" cannot avoid seriously impeding the task of law enforcement, see, e. g., n. 9, supra. If, as the Illinois Supreme Court apparently thought, that test must be rigorously applied in every case, anonymous tips would be of greatly diminished value in police work. Ordinary citizens, like ordinary witnesses, see Advisory Committee's Notes on Fed. Rule Evid. 701, 28 U. S. C. App., p. 570, generally do not provide extensive recitations of the basis of their everyday observations. Likewise, as the Illinois Supreme Court observed in this case, the veracity of persons supplying anonymous tips is by hypothesis largely unknown, and unknowable. As a result, anonymous tips seldom could survive a rigorous application of either of the Spinelli prongs. Yet, such tips, particularly when supplemented by
For all these reasons, we conclude that it is wiser to abandon the "two-pronged test" established by our decisions in Aguilar and Spinelli.
Our earlier cases illustrate the limits beyond which a magistrate may not venture in issuing a warrant. A sworn statement of an affiant that "he has cause to suspect and does believe" that liquor illegally brought into the United States is located on certain premises will not do. Nathanson v. United States, 290 U.S. 41 (1933). An affidavit must provide the magistrate with a substantial basis for determining the existence of probable cause, and the wholly conclusory statement at issue in Nathanson failed to meet this requirement. An officer's statement that "[a]ffiants have received reliable information from a credible person and do believe" that heroin is stored in a home, is likewise inadequate. Aguilar v. Texas, 378 U.S. 108 (1964). As in Nathanson, this is a mere conclusory statement that gives the magistrate virtually no basis at all for making a judgment regarding probable cause. Sufficient information must be presented to the magistrate to allow that official to determine probable cause; his action cannot be a mere ratification of the bare conclusions of others. In order to ensure that such an abdication of the magistrate's duty does not occur, courts must continue to conscientiously review the sufficiency of affidavits on which warrants are issued. But when we move beyond the "bare bones" affidavits present in cases such as Nathanson and Aguilar, this area simply does not lend itself to a prescribed set of rules, like that which had developed from Spinelli. Instead, the flexible, common-sense standard articulated in Jones, Ventresca, and Brinegar better serves the purposes of the Fourth Amendment's probable-cause requirement.
JUSTICE BRENNAN'S dissent suggests in several places that the approach we take today somehow downgrades the
The real gist of JUSTICE BRENNAN'S criticism seems to be a second argument, somewhat at odds with the first, that magistrates should be restricted in their authority to make probable-cause determinations by the standards laid down in Aguilar and Spinelli, and that such findings "should not be authorized unless there is some assurance that the information on which they are based has been obtained in a reliable way by an honest or credible person." Post, at 283. However, under our opinion magistrates remain perfectly free to exact such assurances as they deem necessary, as well as those required by this opinion, in making probable-cause determinations. JUSTICE BRENNAN would apparently prefer that magistrates be restricted in their findings of probable cause by the development of an elaborate body of case law dealing with the "veracity" prong of the Spinelli test, which in turn is broken down into two "spurs" — the informant's "credibility" and the "reliability" of his information, together with the "basis of knowledge" prong of the Spinelli test. See n. 4, supra. That such a labyrinthine body of judicial refinement bears any relationship to familiar definitions of
JUSTICE BRENNAN'S dissent also suggests that "[w]ords such as `practical,' `nontechnical,' and `common sense,' as used in the Court's opinion, are but code words for an overly permissive attitude towards police practices in derogation of the rights secured by the Fourth Amendment." Post, at 290. An easy, but not a complete, answer to this rather florid statement would be that nothing we know about Justice Rutledge suggests that he would have used the words he chose in Brinegar in such a manner. More fundamentally, no one doubts that "under our Constitution only measures consistent with the Fourth Amendment may be employed by government to cure [the horrors of drug trafficking]," post, at 290; but this agreement does not advance the inquiry as to which measures are, and which measures are not, consistent with the Fourth Amendment. "Fidelity" to the commands of the Constitution suggests balanced judgment rather than exhortation. The highest "fidelity" is not achieved by the judge who instinctively goes furthest in upholding even the most bizarre claim of individual constitutional rights, any more than it is achieved by a judge who instinctively goes furthest in accepting the most restrictive claims of governmental authorities. The task of this Court, as of other courts, is to "hold the balance true," and we think we have done that in this case.
Our decisions applying the totality-of-the-circumstances analysis outlined above have consistently recognized the value of corroboration of details of an informant's tip by independent police work. In Jones v. United States, 362 U. S., at 269, we held that an affidavit relying on hearsay "is not to
Our decision in Draper v. United States, 358 U.S. 307 (1959), however, is the classic case on the value of corroborative efforts of police officials. There, an informant named Hereford reported that Draper would arrive in Denver on a train from Chicago on one of two days, and that he would be carrying a quantity of heroin. The informant also supplied a fairly detailed physical description of Draper, and predicted that he would be wearing a light colored raincoat, brown slacks, and black shoes, and would be walking "real fast." Id., at 309. Hereford gave no indication of the basis for his information.
On one of the stated dates police officers observed a man matching this description exit a train arriving from Chicago; his attire and luggage matched Hereford's report and he was
The showing of probable cause in the present case was fully as compelling as that in Draper. Even standing alone, the facts obtained through the independent investigation of Mader and the DEA at least suggested that the Gateses were involved in drug trafficking. In addition to being a popular vacation site, Florida is well known as a source of narcotics and other illegal drugs. See United States v. Mendenhall, 446 U.S. 544, 562 (1980) (POWELL, J., concurring in part and concurring in judgment); DEA, Narcotics Intelligence Estimate, The Supply of Drugs to the U. S. Illicit Market From Foreign and Domestic Sources in 1980, pp. 8-9. Lance Gates' flight to West Palm Beach, his brief, overnight stay in a motel, and apparent immediate return north to Chicago in the family car, conveniently awaiting him in West Palm Beach, is as suggestive of a prearranged drug run, as it is of an ordinary vacation trip.
In addition, the judge could rely on the anonymous letter, which had been corroborated in major part by Mader's efforts — just as had occurred in Draper.
Finally, the anonymous letter contained a range of details relating not just to easily obtained facts and conditions existing at the time of the tip, but to future actions of third parties ordinarily not easily predicted. The letterwriter's accurate information as to the travel plans of each of the Gateses was of a character likely obtained only from the Gateses themselves, or from someone familiar with their not entirely ordinary travel plans. If the informant had access to accurate information of this type a magistrate could properly conclude that it was not unlikely that he also had access to reliable information of the Gateses' alleged illegal activities.
In my view, the question regarding modification of the exclusionary rule framed in our order of November 29, 1982, 459 U.S. 1028 (1982), is properly before us and should be addressed. I continue to believe that the exclusionary rule is an inappropriate remedy where law enforcement officials act in the reasonable belief that a search and seizure was consistent with the Fourth Amendment — a position I set forth in Stone v. Powell, 428 U.S. 465, 537-539 (1976). In this case, it was fully reasonable for the Bloomingdale, Ill., police to believe that their search of respondents' house and automobile comported with the Fourth Amendment as the search was conducted pursuant to a judicially issued warrant. The
The Court declines to address the exclusionary rule question because the Illinois courts were not invited to modify the rule in the first instance. The Court's refusal to face this important question cannot be ascribed to jurisdictional limitations. I fully agree that the statute which gives us jurisdiction in this cause, 28 U. S. C. § 1257(3), prevents us from deciding federal constitutional claims raised here for the first time on review of state-court decisions. Cardinale v. Louisiana, 394 U.S. 437, 438-439 (1969). But it is equally well established that " `[n]o particular form of words or phrases is essential, but only that the claim of invalidity and the ground therefor be brought to the attention of the state court with fair precision and in due time.' " Street v. New York, 394 U.S. 576, 584 (1969) (quoting New York ex rel. Bryant v. Zimmerman, 278 U.S. 63, 67 (1928)). Notwithstanding the select and controversial instances in which the Court has reversed a state-court decision for "plain error,"
We have never suggested that the jurisdictional stipulations of § 1257 require that all arguments on behalf of, let alone in opposition to, a federal claim be raised and decided below.
The presentation and decision of respondents' Fourth Amendment claim fully embraces the argument that due to the nature of the alleged Fourth Amendment violation, the seized evidence should not be excluded. Our decisions concerning the scope of the exclusionary rule cannot be divorced from the Fourth Amendment; they rest on the relationship of Fourth Amendment interests to the objectives of the criminal justice system. See, e. g., United States v. Ceccolini, 435 U.S. 268 (1978); Stone v. Powell, 428 U.S. 465 (1976).
As a jurisdictional requirement, I have no doubt that the exclusionary rule question is before us as an indivisible element of the claim that the Constitution requires exclusion of certain evidence seized in violation of the Fourth Amendment. As a prudential matter, I am unmoved by the Court's lengthy discourse as to why it must avoid the question. First, the Court turns on its head the axiom that " `due regard for the appropriate relationship of this Court to state courts,' McGoldrick v. Compagnie Generale Transatlantique, 309 U. S., at 434-435, demands that those courts be given an opportunity to consider the constitutionality of the actions of state officials," ante, at 221. This statement, written to explain why a state statute should not be struck down on federal grounds not raised in the state courts,
The Court correctly notes that Illinois may choose to pursue a different course with respect to the state exclusionary rule. If this Court were to formulate a "good-faith" exception to the federal exclusionary rule, the Illinois Supreme Court would be free to consider on remand whether the state exclusionary rule should be modified accordingly. The possibility that it might have relied upon the state exclusionary rule had the "good-faith" question been posed does not constitute independent and adequate state grounds. "The possibility that the state court might have reached the same conclusion if it had decided the question purely as a matter of state law does not create an adequate and independent state ground that relieves this Court of the necessity of considering the federal question." United Air Lines, Inc. v. Mahin, 410 U.S. 623, 630-631 (1973); Beecher v. Alabama, 389 U.S. 35, 37, n. 3 (1967); C. Wright, The Law of Federal Courts § 107, pp. 747-748 (4th ed. 1983). Nor does having the state court first decide whether the federal exclusionary rule should be modified — and presentation of the federal question does not insure that the equivalent state-law issue will be
It also appears that the Court, in disposing of the case, does not strictly follow its own prudential advice. The Illinois Supreme Court found not only a violation of the Fourth Amendment but also of Article I, § 6, of the Illinois Constitution, which also provides assurance against unreasonable searches and seizures. Taking the Court's new prudential standards on their own terms, the Illinois courts should be given the opportunity to consider in the first instance whether a "totality of the circumstances" test should replace the more precise rules of Aguilar and Spinelli. The Illinois Supreme Court may decide to retain the established test for purposes of the State Constitution just as easily as it could decide to retain an unmodified exclusionary rule.
Finally, the Court correctly notes that a fully developed record is helpful if not indispensable for the decision of many issues. I too resist the decision of a constitutional question
The Court's straining to avoid coming to grips with the exclusionary rule issue today may be hard for the country to understand — particularly given earlier statements by some Members of the Court.
The exclusionary rule is a remedy adopted by this Court to effectuate the Fourth Amendment right of citizens "to be secure in their persons, houses, papers and effects, against unreasonable searches and seizures . . . ." Although early opinions suggested that the Constitution required exclusion of all illegally obtained evidence, the exclusionary rule "has never been interpreted to proscribe the introduction of illegally seized evidence in all proceedings or against all persons." Stone v. Powell, 428 U. S., at 486. Because of the inherent trustworthiness of seized tangible evidence and the resulting social costs from its loss through suppression, application
This evolvement in the understanding of the proper scope of the exclusionary rule embraces several lines of cases. First, standing to invoke the exclusionary rule has been limited to situations where the government seeks to use such evidence against the victim of the unlawful search. Brown v. United States, 411 U.S. 223 (1973); Alderman v. United States, 394 U.S. 165 (1969); Wong Sun v. United States, 371 U.S. 471, 491-492 (1963); Rakas v. Illinois, 439 U.S. 128 (1978).
Second, the rule has not been applied in proceedings other than the trial itself. In United States v. Calandra, supra, the Court refused to extend the rule to grand jury proceedings. "Any incremental deterrent effect which might be achieved by extending the rule to grand jury proceedings is uncertain at best. . . . We therefore decline to embrace a view that would achieve a speculative and undoubtedly minimal advance in the deterrence of police misconduct at the expense of substantially impeding the role of the grand jury." 414 U. S., at 351-352. Similarly, in United States v. Janis, 428 U.S. 433 (1976), the exclusionary rule was not extended to forbid the use in federal civil proceedings of evidence illegally seized by state officials, since the likelihood of deterring unlawful police conduct was not sufficient to outweigh the social costs imposed by the exclusion.
A similar balancing approach is employed in our decisions limiting the scope of the exclusionary remedy for Fifth Amendment violations, Oregon v. Hass, 420 U.S. 714 (1975); Harris v. New York, 401 U.S. 222 (1971); Michigan v. Tucker, 417 U.S. 433 (1974), and our cases considering whether Fourth Amendment decisions should be applied retroactively, United States v. Peltier, supra, at 538-539; Williams v. United States, 401 U.S. 646, 654-655 (1971) (plurality opinion); Desist v. United States, 394 U.S. 244, 249-250 (1969); Linkletter v. Walker, 381 U.S. 618, 636-639 (1965). But see United States v. Johnson, 457 U.S. 537 (1982).
These cases reflect that the exclusion of evidence is not a personal constitutional right but a remedy, which, like all remedies, must be sensitive to the costs and benefits of its imposition. The trend and direction of our exclusionary rule decisions indicate not a lesser concern with safeguarding the Fourth Amendment but a fuller appreciation of the high costs incurred when probative, reliable evidence is barred because of investigative error. The primary cost, of course, is that the exclusionary rule interferes with the truthseeking function of a criminal trial by barring relevant and trustworthy evidence.
The suppression doctrine entails other costs as well. It would be surprising if the suppression of evidence garnered in good faith, but by means later found to violate the Fourth Amendment, did not deter legitimate as well as unlawful police activities. To the extent the rule operates to discourage police from reasonable and proper investigative actions, it hinders the solution and even the prevention of crime. A tremendous burden is also placed on the state and federal judicial systems. One study reveals that one-third of federal defendants going to trial file Fourth Amendment suppression motions, and 70% to 90% of these involve formal hearings. General Accounting Office, Comptroller General of the United States, Impact of the Exclusionary Rule on Federal Criminal Prosecutions 10 (1979).
The rule also exacts a heavy price in undermining public confidence in the reasonableness of the standards that govern the criminal justice system. "[A]lthough the [exclusionary] rule is thought to deter unlawful police activity in part through the nurturing of respect for Fourth Amendment values, if applied indiscriminately it may well have the opposite effect of generating disrespect for the law and the administration of justice." Stone v. Powell, 428 U. S., at 490-491. As JUSTICE POWELL observed in Stone v. Powell, supra, at 490: "The disparity in particular cases between the error committed by the police officer and the windfall afforded a guilty defendant by application of the rule is contrary to the idea of proportionality that is essential to the concept of justice."
For these reasons, "application of the [exclusionary] rule has been restricted to those areas where its remedial objectives are thought most efficaciously served." United States
The Court in Peltier continued, id., at 542:
See also United States v. Janis, supra, at 459, n. 35 ("[T]he officers here were clearly acting in good faith . . . a factor that the Court has recognized reduces significantly the potential deterrent effect of exclusion"). The deterrent value of the exclusionary sanction is most effective when officers engage in searches and seizures under circumstances "so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable." Brown v. Illinois, 422 U. S., at 610-611 (POWELL, J., concurring in part). On the
There are several types of Fourth Amendment violations that may be said to fall under the rubric of "good faith." "[T]here will be those occasions where the trial or appellate court will disagree on the issue of probable cause, no matter how reasonable the grounds for arrest appeared to the officer and though reasonable men could easily differ on the question. It also happens that after the events at issue have occurred, the law may change, dramatically or ever so slightly, but in any event sufficiently to require the trial judge to hold that there was not probable cause to make the arrest and to seize the evidence offered by the prosecution. . . ." Stone v. Powell, 428 U. S., at 539-540 (WHITE, J., dissenting). The argument for a good-faith exception is strongest, however, when law enforcement officers have reasonably relied on a judicially issued search warrant.
This Court has never set forth a rationale for applying the exclusionary rule to suppress evidence obtained pursuant to a search warrant; it has simply done so without considering whether Fourth Amendment interests will be advanced. It is my view that they generally will not be. When officers have dutifully obtained a search warrant from a judge or magistrate, and execute the warrant as directed by its terms, exclusion of the evidence thus obtained cannot be expected to deter future reliance on such warrants. The warrant is prima facie proof that the officers acted reasonably in conducting the search or seizure; "[o]nce the warrant issues, there is literally nothing more that the policeman can do in seeking to comply with the law." Stone v. Powell, supra, at 498 (BURGER, C. J., concurring).
Opponents of the proposed "reasonable belief" exception suggest that such a modification would allow magistrates and judges to flout the probable-cause requirements in issuing warrants. This is a novel concept: the exclusionary rule was adopted to deter unlawful searches by police, not to punish the errors of magistrates and judges. Magistrates must be neutral and detached from law enforcement operations and I would not presume that a modification of the exclusionary rule will lead magistrates to abdicate their responsibility to apply the law.
Another objection is that a reasonable-belief exception will encompass all searches and seizures on the frontier of the Fourth Amendment and that such cases will escape review on the question of whether the officer's action was permissible, denying needed guidance from the courts and freezing Fourth Amendment law in its present state. These fears are unjustified. The premise of the argument is that a court must first decide the reasonable-belief issue before turning to the question of whether a Fourth Amendment violation has occurred. I see no need for such an inflexible practice. When a Fourth Amendment case presents a novel question of law whose resolution is necessary to guide future action by law enforcement officers and magistrates, there is sufficient reason for the Court to decide the violation issue before turning to the good-faith question. Indeed, it may be difficult to
Finally, it is contended that a good-faith exception will be difficult to apply in practice. This concern appears grounded in the assumption that courts would inquire into the subjective belief of the law enforcement officers involved. I would eschew such investigations. "[S]ending state and federal courts on an expedition into the minds of police officers would produce a grave and fruitless misallocation of judicial resources." Massachusetts v. Painten, 389 U.S. 560, 565 (1968) (WHITE, J., dissenting). Moreover, "[s]ubjective intent alone . . . does not make otherwise lawful conduct illegal or unconstitutional." Scott v. United States, 436 U.S. 128, 136 (1978). Just last Term, we modified the qualified immunity public officials enjoy in suits seeking damages against federal officials for alleged deprivations of constitutional rights, eliminating the subjective component of the standard. See Harlow v. Fitzgerald, 457 U.S. 800 (1982). Although
Since a majority of the Court deems it inappropriate to address the good-faith issue, I briefly address the question that the Court does reach — whether the warrant authorizing the search and seizure of respondents' car and home was constitutionally valid. Abandoning the "two-pronged test" of Aguilar v. Texas, 378 U.S. 108 (1964), and Spinelli v. United States, 393 U.S. 410 (1969), the Court upholds the validity of the warrant under a new "totality of the circumstances" approach. Although I agree that the warrant should be upheld, I reach this conclusion in accordance with the Aguilar-Spinelli framework.
For present purposes, the Aguilar-Spinelli rules can be summed up as follows. First, an affidavit based on an informant's tip, standing alone, cannot provide probable cause for issuance of a warrant unless the tip includes information that apprises the magistrate of the informant's basis for concluding that the contraband is where he claims it is (the "basis of knowledge" prong), and the affiant informs the magistrate of his basis for believing that the informant is credible (the "veracity" prong). Aguilar, supra, at 114;
In the present case, it is undisputed that the anonymous tip, by itself, did not furnish probable cause. The question is whether those portions of the affidavit describing the results of the police investigation of the respondents, when considered in light of the tip, "would permit the suspicions engendered by the informant's report to ripen into a judgment that a crime was probably being committed." Spinelli, supra, at 418. The Illinois Supreme Court concluded that the corroboration was insufficient to permit such a ripening. 85 Ill.2d 376, 387, 423 N.E.2d 887, 892 (1981). The court reasoned as follows:
In my view, the lower court's characterization of the Gateses' activity here as totally "innocent" is dubious. In fact, the behavior was quite suspicious. I agree with the Court, ante, at 243, that Lance Gates' flight to West Palm Beach, an area known to be a source of narcotics, the brief overnight stay in a motel, and apparent immediate return north, suggest a pattern that trained law enforcement officers have recognized as indicative of illicit drug-dealing activity.
Even, however, had the corroboration related only to completely innocuous activities, this fact alone would not preclude the issuance of a valid warrant. The critical issue is not whether the activities, observed by the police are innocent or suspicious. Instead, the proper focus should be on whether the actions of the suspects, whatever their nature, give rise to an inference that the informant is credible and that he obtained his information in a reliable manner.
Thus, in Draper v. United States, 358 U.S. 307 (1959), an informant stated on September 7 that Draper would be carrying narcotics when he arrived by train in Denver on the morning of September 8 or September 9. The informant also provided the police with a detailed physical description
The Court agrees that the warrant was valid, but, in the process of reaching this conclusion, it overrules the Aguilar-Spinelli tests and replaces them with a "totality of the circumstances" standard. As shown above, it is not at all necessary to overrule Aguilar-Spinelli in order to reverse the judgment below. Therefore, because I am inclined to believe that, when applied properly, the Aguilar-Spinelli rules play an appropriate role in probable-cause determinations, and because the Court's holding may foretell an evisceration of the probable-cause standard, I do not join the Court's holding.
The Court reasons, ante, at 233, that the "veracity" and "basis of knowledge" tests are not independent, and that a deficiency as to one can be compensated for by a strong showing as to the other. Thus, a finding of probable cause may be based on a tip from an informant "known for the unusual reliability of his predictions" or from "an unquestionably honest citizen," even if the report fails thoroughly to set forth the basis upon which the information was obtained. Ibid. If this is so, then it must follow a fortiori that "the affidavit of an officer, known by the magistrate to be honest and experienced, stating that [contraband] is located in a certain building" must be acceptable. Spinelli, 393 U. S., at 424 (WHITE, J., concurring). It would be "quixotic" if a similar statement from an honest informant, but not one from an honest officer, could furnish probable cause. Ibid. But we have repeatedly held that the unsupported assertion or belief of an officer does not satisfy the probable-cause requirement. See, e. g., Whiteley v. Warden, 401 U.S. 560, 564-565
The Court may not intend so drastic a result. Indeed, the Court expressly reaffirms, ante, at 239, the validity of cases such as Nathanson that have held that, no matter how reliable the affiant-officer may be, a warrant should not be issued unless the affidavit discloses supporting facts and circumstances. The Court limits these cases to situations involving affidavits containing only "bare conclusions" and holds that, if an affidavit contains anything more, it should be left to the issuing magistrate to decide, based solely on "practical[ity]" and "common sense," whether there is a fair probability that contraband will be found in a particular place. Ante, at 238-239.
Thus, as I read the majority opinion, it appears that the question whether the probable-cause standard is to be diluted is left to the common-sense judgments of issuing magistrates. I am reluctant to approve any standard that does not expressly require, as a prerequisite to issuance of a warrant, some showing of facts from which an inference may be drawn that the informant is credible and that his information was obtained in a reliable way. The Court is correctly concerned with the fact that some lower courts have been applying Aguilar-Spinelli in an unduly rigid manner.
Although I join JUSTICE STEVENS' dissenting opinion and agree with him that the warrant is invalid even under the Court's newly announced "totality of the circumstances" test, see post, at 294-295, and n. 8, I write separately to dissent from the Court's unjustified and ill-advised rejection of the two-prong test for evaluating the validity of a warrant based on hearsay announced in Aguilar v. Texas, 378 U.S. 108 (1964), and refined in Spinelli v. United States, 393 U.S. 410 (1969).
The Court's current Fourth Amendment jurisprudence, as reflected by today's unfortunate decision, patently disregards Justice Jackson's admonition in Brinegar v. United States, 338 U.S. 160 (1949):
In recognition of the judiciary's role as the only effective guardian of Fourth Amendment rights, this Court has developed over the last half century a set of coherent rules governing a magistrate's consideration of a warrant application and the showings that are necessary to support a finding of probable cause. We start with the proposition that a neutral and detached magistrate, and not the police, should determine whether there is probable cause to support the issuance of a warrant. In Johnson v. United States, 333 U.S. 10 (1948), the Court stated:
See also Whiteley v. Warden, 401 U.S. 560, 564 (1971); Spinelli v. United States, supra, at 415; United States v. Ventresca, 380 U.S. 102, 109 (1965); Aguilar v. Texas, supra, at 111; Jones v. United States, 362 U.S. 257, 270-271
In order to emphasize the magistrate's role as an independent arbiter of probable cause and to insure that searches or seizures are not effected on less than probable cause, the Court has insisted that police officers provide magistrates with the underlying facts and circumstances that support the officers' conclusions. In Nathanson v. United States, 290 U.S. 41 (1933), the Court held invalid a search warrant that was based on a customs agent's "mere affirmation of suspicion and belief without any statement of adequate supporting facts." Id., at 46. The Court stated: "Under the Fourth Amendment, an officer may not properly issue a warrant to search a private dwelling unless he can find probable cause therefor from facts or circumstances presented to him under oath or affirmation. Mere affirmance of belief or suspicion is not enough." Id., at 47.
In Giordenello v. United States, supra, the Court reviewed an arrest warrant issued under the Federal Rules of Criminal Procedure based on a complaint sworn to by a Federal Bureau of Narcotics agent. Id., at 481.
As noted, the Court did not decide the hearsay question lurking in Giordenello. The use of hearsay to support the issuance of a warrant presents special problems because informants, unlike police officers, are not regarded as presumptively reliable or honest. Moreover, the basis for an informant's conclusions is not always clear from an affidavit that merely reports those conclusions. If the conclusory allegations of a police officer are insufficient to support a finding of probable cause, surely the conclusory allegations of an informant should a fortiori be insufficient.
In Jones v. United States, supra, the Court considered "whether an affidavit which sets out personal observations relating to the existence of cause to search is to be deemed insufficient by virtue of the fact that it sets out not the affiant's observations but those of another." Id., at 269. The Court held that hearsay information can support the issuance of a warrant "so long as a substantial basis for crediting the hearsay is presented." Ibid. The Court found that there was a substantial basis for crediting the hearsay involved in Jones. The informant's report was based on the informant's personal knowledge, and the informant previously had provided accurate information. Moreover, the informant's story was corroborated by other sources. Finally, the defendant was known to the police to be a narcotics user. Id., at 271.
Aguilar v. Texas, 378 U.S. 108 (1964), merely made explicit what was implicit in Jones. In considering a search warrant based on hearsay, the Court reviewed Nathanson
While recognizing that a warrant may be based on hearsay, the Court established the following standard:
The Aguilar standard was refined in Spinelli v. United States, 393 U.S. 410 (1969). In Spinelli, the Court reviewed a search warrant based on an affidavit that was "more ample," id., at 413, than the one in Aguilar. The affidavit in Spinelli contained not only a tip from an informant, but also a report of an independent police investigation that allegedly corroborated the informant's tip. 393 U. S., at 413. Under these circumstances, the Court stated that it was "required to delineate the manner in which Aguilar's two-pronged test should be applied . . . ." Ibid.
The Court held that the Aguilar test should be applied to the tip, and approved two additional ways of satisfying that test. First, the Court suggested that if the tip contained sufficient detail describing the accused's criminal activity it might satisfy Aguilar's basis of knowledge prong. 393 U. S., at 416. Such detail might assure the magistrate that he is "relying on something more substantial than a casual rumor circulating in the underworld or an accusation based merely on an individual's general reputation." Ibid. Although the tip in the case before it did not meet this standard, "[t]he detail provided by the informant in Draper v. United States, 358 U.S. 307 (1959), provide[d] a suitable benchmark," ibid., because "[a] magistrate, when confronted with such detail, could reasonably infer that the informant
Second, the Court stated that police corroboration of the details of a tip could provide a basis for satisfying Aguilar.
I find this reasoning persuasive. Properly understood, therefore, Spinelli stands for the proposition that corroboration of certain details in a tip may be sufficient to satisfy the veracity, but not the basis of knowledge, prong of Aguilar. As noted, Spinelli also suggests that in some limited circumstances considerable detail in an informant's tip may be adequate to satisfy the basis of knowledge prong of Aguilar.
Until today the Court has never squarely addressed the application of the Aguilar and Spinelli standards to tips from anonymous informants. Both Aguilar and Spinelli dealt with tips from informants known at least to the police. See also, e. g., Adams v. Williams, 407 U.S. 143, 146 (1972); United States v. Harris, 403 U.S. 573, 575 (1971); Whiteley v. Warden, 401 U. S., at 565; McCray v. Illinois, 386 U.S. 300,
To suggest that anonymous informants' tips are subject to the tests established by Aguilar and Spinelli is not to suggest that they can never provide a basis for a finding of probable cause. It is conceivable that police corroboration of the details of the tip might establish the reliability of the informant under Aguilar's veracity prong, as refined in Spinelli, and that the details in the tip might be sufficient to qualify under the "self-verifying detail" test established by Spinelli as a means of satisfying Aguilar's basis of knowledge prong. The Aguilar and Spinelli tests must be applied to anonymous informants' tips, however, if we are to continue to insure
In light of the important purposes served by Aguilar and Spinelli, I would not reject the standards they establish. If anything, I simply would make more clear that Spinelli, properly understood, does not depart in any fundamental way from the test established by Aguilar. For reasons I shall next state, I do not find persuasive the Court's justifications for rejecting the test established by Aguilar and refined by Spinelli.
In rejecting the Aguilar-Spinelli standards, the Court suggests that a "totality-of-the-circumstances approach is far more consistent with our prior treatment of probable cause than is any rigid demand that specific `tests' be satisfied by every informant's tip." Ante, at 230-231 (footnote omitted). In support of this proposition the Court relies on several cases that purportedly reflect this approach, ante, at 230-231, n. 6, 232-233, n. 7, and on the "practical, nontechnical," ante, at 231, nature of probable cause.
Only one of the cases cited by the Court in support of its "totality of the circumstances" approach, Jaben v. United States, 381 U.S. 214 (1965), was decided subsequent to Aguilar. It is by no means inconsistent with Aguilar.
In addition, one can concede that probable cause is a "practical, nontechnical" concept without betraying the values that Aguilar and Spinelli reflect. As noted, see supra, at 277-282, Aguilar and Spinelli require the police to provide magistrates with certain crucial information. They also provide structure for magistrates' probable-cause inquiries. In so doing, Aguilar and Spinelli preserve the role of magistrates as independent arbiters of probable cause, insure greater accuracy in probable-cause determinations, and advance the substantive value of precluding findings of probable cause, and attendant intrusions, based on anything less than information from an honest or credible person who has acquired his information in a reliable way. Neither the standards nor their effects are inconsistent with a "practical, nontechnical" conception of probable cause. Once a magistrate has determined that he has information before him that he can reasonably say has been obtained in a reliable way by a credible person, he has ample room to use his common sense and to apply a practical, nontechnical conception of probable cause.
It also should be emphasized that cases such as Nathanson v. United States, 290 U.S. 41 (1933), and Giordenello v. United States, 357 U.S. 480 (1958), discussed supra, at 276-277, directly contradict the Court's suggestion, ante, at 233, that a strong showing on one prong of the Aguilar test should compensate for a deficient showing on the other. If the conclusory allegations of a presumptively reliable police officer are insufficient to establish probable cause, there is no conceivable reason why the conclusory allegations of an anonymous informant should not be insufficient as well. Moreover, contrary to the Court's implicit suggestion, Aguilar and Spinelli do not stand as an insuperable barrier to the use
The Court also insists that the Aguilar-Spinelli standards must be abandoned because they are inconsistent with the fact that nonlawyers frequently serve as magistrates. Ante, at 235-236. To the contrary, the standards help to structure probable-cause inquiries and, properly interpreted, may actually help a nonlawyer magistrate in making a probable-cause determination. Moreover, the Aguilar and Spinelli tests are not inconsistent with deference to magistrates' determinations of probable cause. Aguilar expressly acknowledged that reviewing courts "will pay substantial deference to judicial determinations of probable cause . . . ." 378 U. S., at 111. In Spinelli, the Court noted that it was not retreating from the proposition that magistrates' determinations of probable cause "should be paid great deference by reviewing courts . . . ." 393 U. S., at 419. It is also noteworthy that the language from United States v. Ventresca, 380 U. S., at 108-109, which the Court repeatedly quotes, see ante, at 235, 236, and 237, n. 10, brackets the following passage, which the Court does not quote:
At the heart of the Court's decision to abandon Aguilar and Spinelli appears to be its belief that "the direction taken by decisions following Spinelli poorly serves `[t]he most basic function of any government': `to provide for the security of the individual and of his property.' " Ante, at 237. This conclusion rests on the judgment that Aguilar and Spinelli "seriously imped[e] the task of law enforcement," ante, at 237, and render anonymous tips valueless in police work. Ibid. Surely, the Court overstates its case. See supra, at 287-288. But of particular concern to all Americans must be that the Court gives virtually no consideration to the value of insuring that findings of probable cause are based on information that a magistrate can reasonably say has been obtained in a reliable
The Court's complete failure to provide any persuasive reason for rejecting Aguilar and Spinelli doubtlessly reflects impatience with what it perceives to be "overly technical" rules governing searches and seizures under the Fourth Amendment. Words such as "practical," "nontechnical," and "common sense," as used in the Court's opinion, are but code words for an overly permissive attitude towards police practices in derogation of the rights secured by the Fourth Amendment. Everyone shares the Court's concern over the horrors of drug trafficking, but under our Constitution only measures consistent with the Fourth Amendment may be employed by government to cure this evil. We must be ever mindful of Justice Stewart's admonition in Coolidge v. New Hampshire, 403 U.S. 443 (1971): "In times of unrest, whether caused by crime or racial conflict or fear of internal subversion, this basic law and the values that it represents may appear unrealistic or `extravagant' to some. But the values were those of the authors of our fundamental constitutional concepts." Id., at 455 (plurality opinion). In the same vein, Glasser v. United States, 315 U.S. 60 (1942), warned that "[s]teps innocently taken may, one by one, lead to the irretrievable impairment of substantial liberties." Id., at 86.
Rights secured by the Fourth Amendment are particularly difficult to protect because their "advocates are usually criminals." Draper v. United States, 358 U. S., at 314 (Douglas, J., dissenting). But the rules "we fashion [are] for the innocent and guilty alike." Ibid. See also Kolender v. Lawson, 461 U.S. 352, 362, n. 1 (1983) (BRENNAN, J., concurring); Brinegar v. United States, 338 U. S., at 181 (Jackson, J., dissenting).
JUSTICE STEVENS, with whom JUSTICE BRENNAN joins, dissenting.
The fact that Lance and Sue Gates made a 22-hour nonstop drive from West Palm Beach, Florida, to Bloomingdale, Illinois, only a few hours after Lance had flown to Florida provided persuasive evidence that they were engaged in illicit activity. That fact, however, was not known to the judge when he issued the warrant to search their home.
What the judge did know at that time was that the anonymous informant had not been completely accurate in his or her predictions. The informant had indicated that " `Sue . . . drives their car to Florida where she leaves it to be loaded up with drugs . . . . Sue fl[ies] back after she drops the car off in Florida.' " 85 Ill.2d 376, 379, 423 N.E.2d 887, 888 (1981) (emphasis added). Yet Detective Mader's affidavit reported that she " `left the West Palm Beach area driving the Mercury northbound.' " 82 Ill.App.3d 749, 757, 403 N.E.2d 77, 82 (1980).
The discrepancy between the informant's predictions and the facts known to Detective Mader is significant for three reasons. First, it cast doubt on the informant's hypothesis that the Gates already had " `over [$100,000] worth of drugs in their basement,' " 85 Ill. 2d, at 379, 423 N. E. 2d, at 888. The informant had predicted an itinerary that always kept one
Second, the discrepancy made the Gates' conduct seem substantially less unusual than the informant had predicted it would be. It would have been odd if, as predicted, Sue had driven down to Florida on Wednesday, left the car, and flown right back to Illinois. But the mere facts that Sue was in West Palm Beach with the car,
Of course, the activities in this case did not stop when the judge issued the warrant. The Gates drove all night to Bloomingdale, the officers searched the car and found 400 pounds of marihuana, and then they searched the house.
Although the foregoing analysis is determinative as to the house search, the car search raises additional issues because "there is a constitutional difference between houses and cars." Chambers v. Maroney, 399 U.S. 42, 52 (1970). Cf. Payton v. New York, 445 U.S. 573, 589-590 (1980). An officer who has probable cause to suspect that a highly movable automobile contains contraband does not need a valid warrant in order to search it. This point was developed in our opinion in United States v. Ross, 456 U.S. 798 (1982), which was not decided until after the Illinois Supreme Court rendered its decision in this case. Under Ross, the car search may have been valid if the officers had probable cause after the Gates arrived.
In apologizing for its belated realization that we should not have ordered reargument in this case, the Court today shows high regard for the appropriate relationship of this Court to state courts. Ante, at 221-222. When the Court discusses the merits, however, it attaches no weight to the conclusions of the Circuit Judge of Du Page County, Illinois, of the three judges of the Second District of the Illinois Appellate Court, or of the five justices of the Illinois Supreme Court, all of whom concluded that the warrant was not based on probable cause. In a fact-bound inquiry of this sort, the judgment of three levels of state courts, all of which are better able to evaluate the probable reliability of anonymous informants in
The decision in Stanley, while expressly approving and conscientiously attempting to apply the "two-pronged test" observes that "[t]he built-in subtleties [of the test] are such, however, that a slipshod application calls down upon us the fury of Murphy's Law." 19 Md. App., at 528, 313 A. 2d, at 860 (footnote omitted). The decision also suggested that it is necessary to "evolve analogous guidelines [to hearsay rules employed in trial settings] for the reception of hearsay in a probable cause setting." Id., at 522, n. 12, 313 A. 2d, at 857, n. 12.
"the magistrate must be informed of some of the underlying circumstances from which the informant concluded that . . . narcotics were where he claimed they were, and some of the underlying circumstances from which the officer concluded that the informant . . . was `credible' or his information `reliable.' " Id., at 114 (emphasis added).
As our language indicates, we intended neither a rigid compartmentalization of the inquiries into an informant's "veracity," "reliability," and "basis of knowledge," nor that these inquiries be elaborate exegeses of an informant's tip. Rather, we required only that some facts bearing on two particular issues be provided to the magistrate. Our decision in Jaben v. United States, 381 U.S. 214 (1965), demonstrated this latter point. We held there that a criminal complaint showed probable cause to believe the defendant had attempted to evade the payment of income taxes. We commented:
"Obviously any reliance upon factual allegations necessarily entails some degree of reliability upon the credibility of the source. . . . Nor does it indicate that each factual allegation which the affiant puts forth must be independently documented, or that each and every fact which contributed to his conclusions be spelled out in the complaint. . . . It simply requires that enough information be presented to the Commissioner to enable him to make the judgment that the charges are not capricious and are sufficiently supported to justify bringing into play the further steps of the criminal process." Id., at 224-225 (emphasis added).
Likewise, in Rugendorf v. United States, 376 U.S. 528 (1964), the Court upheld a magistrate's determination that there was probable cause to believe that certain stolen property would be found in petitioner's apartment. The affidavit submitted to the magistrate stated that certain furs had been stolen, and that a confidential informant, who previously had furnished confidential information, said that the saw the furs in petitioner's home. Moreover, another confidential informant, also claimed to be reliable, stated that one Schweihs had stolen the furs. Police reports indicated that petitioner had been seen in Schweihs' company, and a third informant stated that petitioner was a fence for Schweihs.
Finally, in Ker v. California, 374 U.S. 23 (1963), we held that information within the knowledge of officers who searched the Kers' apartment provided them with probable cause to believe drugs would be found there. The officers were aware that one Murphy had previously sold marihuana to a police officer; the transaction had occurred in an isolated area, to which Murphy had led the police. The night after this transaction, police observed Mr. Ker and Murphy meet in the same location. Murphy approached Ker's car, and, although police could see nothing change hands, Murphy's modus operandi was identical to what it had been the night before. Moreover, when police followed Ker from the scene of the meeting with Murphy he managed to lose them after performing an abrupt U-turn. Finally, the police had a statement from an informant who had provided reliable information previously, that Ker was engaged in selling marihuana, and that his source was Murphy. We concluded that "[t]o say that this coincidence of information was sufficient to support a reasonable belief of the officers that Ker was illegally in possession of marijuana is to indulge in understatement." Id., at 36.
Likewise, in People v. Palanza, 55 Ill.App.3d 1028, 371 N.E.2d 687 (1978), the affidavit submitted in support of an application for a search warrant stated that an informant of proven and uncontested reliability had seen, in specifically described premises, "a quantity of a white crystalline substance which was represented to the informant by a white male occupant of the premises to be cocaine. Informant has observed cocaine on numerous occasions in the past and is thoroughly familiar with its appearance. The informant states that the white crystalline powder he observed in the above described premises appeared to him to be cocaine." Id., at 1029, 371 N. E. 2d, at 688. The warrant issued on the basis of the affidavit was invalidated because "[t]here is no indication as to how the informant or for that matter any other person could tell whether a white substance was cocaine and not some other substance such as sugar or salt." Id., at 1030, 371 N. E. 2d, at 689.
Finally, in People v. Brethauer, 174 Colo. 29, 482 P.2d 369 (1971), an informant, stated to have supplied reliable information in the past, claimed that L. S. D. and marihuana were located on certain premises. The informant supplied police with drugs, which were tested by police and confirmed to be illegal substances. The affidavit setting forth these, and other, facts was found defective under both prongs of Spinelli.
Whether the allegations submitted to the magistrate in Spinelli would, under the view we now take, have supported a finding of probable cause, we think it would not be profitable to decide. There are so many variables in the probable-cause equation that one determination will seldom be a useful "precedent" for another. Suffice it to say that while we in no way abandon Spinelli's concern for the trustworthiness of informers and for the principle that it is the magistrate who must ultimately make a finding of probable cause, we reject the rigid categorization suggested by some of its language.
This is perfectly reasonable. As discussed previously, probable cause requires only a probability or substantial chance of criminal activity, not an actual showing of such activity. By hypothesis, therefore, innocent behavior frequently will provide the basis for a showing of probable cause; to require otherwise would be to sub silentio impose a drastically more rigorous definition of probable cause than the security of our citizens' demands. We think the Illinois court attempted a too rigid classification of the types of conduct that may be relied upon in seeking to demonstrate probable cause. See Brown v. Texas, 443 U.S. 47, 52, n. 2 (1979). In making a determination of probable cause the relevant inquiry is not whether particular conduct is "innocent" or "guilty," but the degree of suspicion that attaches to particular types of noncriminal acts.
Likewise, there is no force to the dissent's argument that the Gateses' action in leaving their home unguarded undercut the informants claim that drugs were hidden there. Indeed, the line-by-line scrutiny that the dissent applies to the anonymous letter is akin to that which we find inappropriate in reviewing magistrates' decisions. The dissent apparently attributes to the judge who issued the warrant in this case the rather implausible notion that persons dealing in drugs always stay at home, apparently out of fear that to leave might risk intrusion by criminals. If accurate, one could not help sympathizing with the self-imposed isolation of people so situated. In reality, however, it is scarcely likely that the judge ever thought that the anonymous tip "kept one spouse" at home, much less that he relied on the theory advanced by the dissent. The letter simply says that Sue would fly from Florida to Illinois, without indicating whether the Gateses made the bitter choice of leaving the drugs in their house, or those in their car, unguarded. The judge's determination that there might be drugs or evidence of criminal activity in the Gateses' home was well supported by the less speculative theory, noted in text, that if the informant could predict with considerable accuracy the somewhat unusual travel plans of the Gateses, he probably also had a reliable basis for his statements that the Gateses kept a large quantity of drugs in their home and frequently were visited by other drug traffickers there.
"In cases coming here from state courts in which a state statute is assailed as unconstitutional, there are reasons of peculiar force which should lead us to refrain from deciding questions not presented or decided in the highest court of the state whose judicial action we are called upon to review. Apart from the reluctance with which every court should proceed to set aside legislation as unconstitutional on grounds not properly presented, due regard for the appropriate relationship of this Court to state courts requires us to decline to consider and decide questions affecting the validity of state statutes not urged or considered there. It is for these reasons that this Court, where the constitutionality of a statute has been upheld in the state court, consistently refuses to consider any grounds of attack not raised or decided in that court."
I recognize that we have held that the exclusionary rule required suppression of evidence obtained in searches carried out pursuant to statutes, not previously declared unconstitutional, which purported to authorize the searches in question without probable cause and without a valid warrant. See, e. g., Torres v. Puerto Rico, 442 U.S. 465 (1979); Almeida-Sanchez v. United States, supra; Sibron v. New York, 392 U.S. 40 (1968); Berger v. New York, 388 U.S. 41 (1967). The results in these cases may well be different under a "good-faith" exception to the exclusionary rule.
Indeed, the present indiscriminate application of the exclusionary rule may hinder the educative and deterrent function of the suppression remedy. "Instead of disciplining their employees, police departments generally have adopted the attitude that the courts cannot be satisfied, that the rules are hopelessly complicated and subject to change, and that the suppression of evidence is the court's problem and not the departments'." Kaplan, The Limits of the Exclusionary Rule, 26 Stan. L. Rev. 1027, 1050 (1974). If evidence is suppressed only when a law enforcement officer should have known that he was violating the Fourth Amendment, police departments may look more seriously at the officer's misconduct when suppression is invoked. Moreover, by providing that evidence gathered in good-faith reliance on a reasonable rule will not be excluded, a good-faith exception creates an incentive for police departments to formulate rules governing activities of officers in the search-and-seizure area. Many commentators, including proponents of the exclusionary sanction, recognize that the formulation of such rules by police departments, and the training necessary to implement these guidelines in practice, are perhaps the most effective means of protecting Fourth Amendment rights. See K. Davis, Discretionary Justice (1969); McGowan, Rule-Making and the Police, 70 Mich. L. Rev. 659 (1972); Amsterdam, Perspectives on the Fourth Amendment, 58 Minn. L. Rev. 349, 416-431 (1974).
JUSTICE BRENNAN, post, at 280, n. 3, 281-282, erroneously interprets my Spinelli concurrence as espousing the view that "corroboration of certain details in a tip may be sufficient to satisfy the veracity, but not the basis of knowledge, prong of Aguilar." Others have made the same mistake. See, e. g., Comment, 20 Am. Crim. L. Rev. 99, 105 (1982). I did not say that corroboration could never satisfy the "basis of knowledge" prong. My concern was, and still is, that the prong might be deemed satisfied on the basis of corroboration of information that does not in any way suggest that the informant had an adequate basis of knowledge for his report. If, however, as in Draper, the police corroborate information from which it can be inferred that the informant's tip was grounded on inside information, this corroboration is sufficient to satisfy the "basis of knowledge" prong. Spinelli, 393 U. S., at 426 (WHITE, J., concurring). The rules would indeed be strange if, as JUSTICE BRENNAN suggests, post, at 284, the "basis of knowledge" prong could be satisfied by detail in the tip alone, but not by independent police work.
"A police officer who arrived at the `suspicion,' `belief' or `mere conclusion' that narcotics were in someone's possession could not obtain a warrant. But he could convey this conclusion to another police officer, who could then secure the warrant by swearing that he had `received reliable information from a credible person' that the narcotics were in someone's possession." Ibid.
On the second morning specified by the informant, the police saw a man "having the exact physical attributes and wearing the precise clothing described by [the informant], alight from an incoming Chicago train and start walking `fast' toward the exit." Id., at 309-310. The man was carrying a tan zipper bag. The police arrested him and searched him incident to the arrest. Id., at 310.
The Court found that the arrest had been based on probable cause. Having verified every detail of the tip "except whether [Draper] had accomplished his mission and had the three ounces of heroin on his person or in his bag," id., at 313, the police "had `reasonable grounds' to believe that the remaining unverified bit of [the informant's] information . . . was likewise true." Ibid.
There is no doubt that the tip satisfied Aguilar's veracity prong. The informant had given accurate information in the past. Moreover, under Spinelli, the police corroborated most of the details of the informant's tip. See Spinelli v. United States, 393 U. S., at 417; id., at 426-427 (WHITE, J., concurring); infra, at 281, and n. 4. There is some question, however, about whether the tip satisfied Aguilar's basis of knowledge prong. The fact that an informant is right about most things may suggest that he is credible, but it does not establish that he has acquired his information in a reliable way. See Spinelli v. United States, supra, at 426-427 (WHITE, J., concurring). Spinelli's "self-verifying detail" element resolves this tension. As one commentator has suggested, "under Spinelli, the Draper decision is sound as applied to its facts." Note, the Informer's Tip As Probable Cause for Search or Arrest, 54 Cornell L. Rev. 958, 964, n. 34 (1969).
It is the Court's citation of Draper which creates most of the confusion. The informant's credibility was not at issue in Draper irrespective of the corroboration of the details of his tip. See n. 3, supra. The Court's opinion, therefore, might be read as suggesting that corroboration also could satisfy Aguilar's basis of knowledge test. I think it is more likely, however, especially in view of the discussion infra, this page and 282, that the Court simply was discussing an alternative means of satisfying Aguilar's veracity prong, using the facts of Draper as an example, and relying on its earlier determination that the detail of the tip in Draper was self-verifying. See 393 U. S., at 416-417. It is noteworthy that although the affiant in Spinelli had sworn that the informer was reliable, "he [had] offered the magistrate no reason in support of this conclusion." Id., at 416. Aguilar's veracity prong, therefore, was not satisfied. 393 U. S., at 416.
"This is not to say that the tip was so insubstantial that it could not properly have counted in the magistrate's determination. Rather, it needed some further support. When we look to the other parts of the application, however, we find nothing alleged which would permit the suspicions engendered by the informant's report to ripen into a judgment that a crime was probably being committed." Spinelli v. United States, 393 U. S., at 418.
The Court went on to suggest that corroboration of incriminating facts would be needed. See ibid.
In cases in which the police rely on information obtained from an anonymous informant, the police, by hypothesis, cannot obtain further information from the informant regarding the facts and circumstances on which the informant based his conclusion. When the police seek a warrant based solely on an anonymous informant's tip, therefore, they are providing the magistrate with all the information on which they have based their conclusion. In this respect, the command of Aguilar and Spinelli has been met and the process value identified above has been served. But Aguilar and Spinelli advance other values which argue for their application even to anonymous informants' tips. They structure the magistrate's probable-cause inquiry and, more importantly, they guard against findings of probable cause, and attendant intrusions, based on anything other than information which magistrates reasonably can conclude has been obtained in a reliable way by an honest or credible person.
"Some offenses are subject to putative establishment by blunt and concise factual allegations, e. g., `A saw narcotics in B's possession,' whereas `A saw B file a false tax return' does not mean very much in a tax evasion case. Establishment of grounds for belief that the offense of tax evasion has been committed often requires a reconstruction of the taxpayer's income from many individually unrevealing facts which are not susceptible of a concise statement in a complaint. Furthermore, unlike narcotics informants, for example, whose credibility may often be suspect, the sources in this tax evasion case are much less likely to produce false or untrustworthy information. Thus, whereas some supporting information concerning the credibility of informants in narcotics cases or other common garden varieties of crime may be required, such information is not so necessary in the context of the case before us." Id., at 223-224.
Obviously, Jaben is not inconsistent with Aguilar and involved no general rejection of the Aguilar standards.
"[T]he most basic constitutional rule in this area is that `searches conducted outside the judicial process, without prior approval by judge or magistrate, are per se unreasonable under the Fourth Amendment — subject only to a few specifically established and well-delineated exceptions.' The exceptions are `jealously and carefully drawn,' and there must be `a showing by those who seek exemption . . . that the exigencies of the situation made that course imperative.' `[T]he burden is on those seeking the exemption to show the need for it.' " Id., at 454-455 (plurality opinion) (footnotes omitted).
It therefore would appear to be not only inadvisable, but also unavailing, for the police to conduct warrantless searches in "the hope of relying on consent or some other exception to the Warrant Clause that might develop at the time of the search." Ante, at 236.