THE PROGRESSIVE VOICE OF REFORM

U.S. Supreme Court

UNITED STATES v. LEON, 468 U.S. 897 (1984)

468 U.S. 897

UNITED STATES v. LEON ET AL.
CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT

No. 82-1771.

Argued January 17, 1984
Decided July 5, 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.

WHITE, J., delivered the opinion of the Court, in which BURGER, C. J., and BLACKMUN, POWELL, REHNQUIST, and O'CONNOR, JJ., joined. BLACKMUN, J., filed a concurring opinion, post, p. 927. BRENNAN, J., filed a dissenting opinion, in which MARSHALL, J., joined, post, p. 928. STEVENS, J., filed a dissenting opinion, post, p. 960.

Solicitor General Lee argued the cause for the United States. With him on the briefs were Assistant Attorney General Trott, Deputy Solicitor General Frey, Kathryn A. Oberly, and Robert J. Erickson.

Barry Tarlow argued the cause for respondent Leon. With him on the brief were Norman Kaplan and Thomas V. Johnston. Roger L. Cossack argued the cause for respondents Stewart et al. With him on the brief was Jay L. Lichtman.

[Footnote *] Briefs of amici curiae urging reversal were filed for the State of California by John K. Van De Kamp, Attorney General, William D. Stein, Chief Assistant Attorney General, and Clifford K. Thompson, Jr., Deputy Attorney General; for the State of Kansas et al. by Wilkes C. Robinson, Dan M. Peterson, Robert T. Stephan, Attorney General of Kansas, John D. Ashcroft, Attorney General of Missouri, Mark V. Meierhenry, Attorney General of South Dakota, and Bronson C. La Follette, Attorney General of Wisconsin; for the Criminal Justice Legal Foundation by Christopher [468 U.S. 897, 900] N. Heard; for the National District Attorneys Association, Inc., by Newman A. Flanagan, Austin J. McGuigan, John M. Massameno, Edwin L. Miller, Jr., Jack E. Yelverton, and James P. Manak; and for Seven Former Members of the Attorney General's Task Force on Violent Crime et al. by David L. Crump, Frank G. Carrington, Griffin B. Bell, Wayne W. Schmidt, James P. Manak, Fred E. Inbau, Rufus L. Edmisten, Attorney General of North Carolina, and David S. Crump, Deputy Attorney General.

Briefs of amici curiae urging affirmance were filed for the Bar Association of San Francisco et al. by James J. Brosnahan; for the Arkansas Trial Lawyers Association et al. by John Wesley Hall, Jr.; for the Association of Trial Lawyers of America by Sidney Bernstein; and for the Texas Criminal Defense Lawyers Association et al. by Gerald H. Goldstein and Marvin Miller.

Briefs of amici curiae were filed for the Committee on Criminal Law of the Association of the Bar of the City of New York by Peter L. Zimroth and Barbara D. Underwood; for the Illinois State Bar Association by Michael J. Costello, Albert Hofeld, William J. Martin, and Joshua Sachs; for the Minnesota State Bar Association by Ronald L. Seeger, Steven H. Goldberg, and Bruce H. Hanley; for the National Association of Criminal Defense Lawyers et al. by Marshall W. Krause, Steffan B. Imhoff, and Charles Scott Spear; for the National Association for the Advancement of Colored People et al. by Steven P. Lockman, John M. Campbell, and Thomas I. Atkins; for the National Legal Aid and Defender Association by Kenneth M. Mogill; and for Dan Johnston, County Attorney, Polk County, Iowa, by Mr. Johnston, pro se. [468 U.S. 897, 900]

JUSTICE WHITE delivered the opinion of the Court.

This case presents the question whether the Fourth Amendment exclusionary rule should be modified so as not 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 unsupported by probable cause. To resolve this question, we must consider once again the tension between the sometimes competing goals of, on the one hand, deterring official misconduct and removing inducements to unreasonable invasions of privacy and, on the other, establishing procedures under which criminal defendants are "acquitted [468 U.S. 897, 901]or convicted on the basis of all the evidence which exposes the truth." Alderman v. United States, 394 U.S. 165, 175 (1969).

I

In August 1981, a confidential informant of unproven reliability informed an officer of the Burbank Police Department that two persons known to him as "Armando" and "Patsy" were selling large quantities of cocaine and methaqualone from their residence at 620 Price Drive in Burbank, Cal. The informant also indicated that he had witnessed a sale of methaqualone by "Patsy" at the residence approximately five months earlier and had observed at that time a shoebox containing a large amount of cash that belonged to "Patsy." He further declared that "Armando" and "Patsy" generally kept only small quantities of drugs at their residence and stored the remainder at another location in Burbank.

On the basis of this information, the Burbank police initiated an extensive investigation focusing first on the Price Drive residence and later on two other residences as well. Cars parked at the Price Drive residence were determined to belong to respondents Armando Sanchez, who had previously been arrested for possession of marihuana, and Patsy Stewart, who had no criminal record. During the course of the investigation, officers observed an automobile belonging to respondent Ricardo Del Castillo, who had previously been arrested for possession of 50 pounds of marihuana, arrive at the Price Drive residence. The driver of that car entered the house, exited shortly thereafter carrying a small paper sack, and drove away. A check of Del Castillo's probation records led the officers to respondent Alberto Leon, whose telephone number Del Castillo had listed as his employer's. Leon had been arrested in 1980 on drug charges, and a companion had informed the police at that time that Leon was heavily involved in the importation of drugs into this country. Before the current investigation began, the Burbank officers had [468 U.S. 897, 902]learned that an informant had told a Glendale police officer that Leon stored a large quantity of methaqualone at his residence in Glendale. During the course of this investigation, the Burbank officers learned that Leon was living at 716 South Sunset Canyon in Burbank.

Subsequently, the officers observed several persons, at least one of whom had prior drug involvement, arriving at the Price Drive residence and leaving with small packages; observed a variety of other material activity at the two residences as well as at a condominium at 7902 Via Magdalena; and witnessed a variety of relevant activity involving respondents' automobiles. The officers also observed respondents Sanchez and Stewart board separate flights for Miami. The pair later returned to Los Angeles together, consented to a search of their luggage that revealed only a small amount of marihuana, and left the airport. Based on these and other observations summarized in the affidavit, App. 34, Officer Cyril Rombach of the Burbank Police Department, an experienced and well-trained narcotics investigator, prepared an application for a warrant to search 620 Price Drive, 716 South Sunset Canyon, 7902 Via Magdalena, and automobiles registered to each of the respondents for an extensive list of items believed to be related to respondents' drug-trafficking activities. Officer Rombach's extensive application was reviewed by several Deputy District Attorneys.

A facially valid search warrant was issued in September 1981 by a State Superior Court Judge. The ensuing searches produced large quantities of drugs at the Via Magdalena and Sunset Canyon addresses and a small quantity at the Price Drive residence. Other evidence was discovered at each of the residences and in Stewart's and Del Castillo's automobiles. Respondents were indicted by a grand jury in the District Court for the Central District of California and charged with conspiracy to possess and distribute cocaine and a variety of substantive counts. [468 U.S. 897, 903]

The respondents then filed motions to suppress the evidence seized pursuant to the warrant.1 The District Court held an evidentiary hearing and, while recognizing that the case was a close one, see id., at 131, granted the motions to suppress in part. It concluded that the affidavit was insufficient to establish probable cause,2 but did not suppress all of the evidence as to all of the respondents because none of the respondents had standing to challenge all of the searches.3 In [468 U.S. 897, 904]response to a request from the Government, the court made clear that Officer Rombach had acted in good faith, but it 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.4

The District Court denied the Government's motion for reconsideration, id., at 147, and a divided panel of the Court of Appeals for the Ninth Circuit affirmed, judgt. order reported at 701 F.2d 187 (1983). The Court of Appeals first concluded that Officer Rombach's affidavit could not establish probable cause to search the Price Drive residence. To the extent that the affidavit set forth facts demonstrating the basis of the informant's knowledge of criminal activity, the information included was fatally stale. The affidavit, moreover, failed to establish the informant's credibility. Accordingly, the Court of Appeals concluded that the information provided by the informant was inadequate under both prongs of the two-part test established in Aguilar v. Texas, 378 U.S. 108 (1964), and Spinelli v. United States, 393 U.S. 410 (1969).5 The officers' independent investigation neither cured the staleness nor corroborated the details of the informant's declarations. The Court of Appeals then considered whether the affidavit formed a proper basis for the [468 U.S. 897, 905] search of the Sunset Canyon residence. In its view, the affidavit included no facts indicating the basis for the informants' statements concerning respondent Leon's criminal activities and was devoid of information establishing the informants' reliability. Because these deficiencies had not been cured by the police investigation, the District Court properly suppressed the fruits of the search. The Court of Appeals refused the Government's invitation to recognize a good-faith exception to the Fourth Amendment exclusionary rule. App. to Pet. for Cert. 4a.

The Government's petition for certiorari expressly declined to seek review of the lower courts' determinations that the search warrant was unsupported by probable cause and presented only the question "[w]hether the Fourth Amendment exclusionary rule should be modified so as not to bar the admission of evidence seized in reasonable, good-faith reliance on a search warrant that is subsequently held to be defective." We granted certiorari to consider the propriety of such a modification. 463 U.S. 1206 (1983). Although it undoubtedly is within our power to consider the question whether probable cause existed under the "totality of the circumstances" test announced last Term in Illinois v. Gates, 462 U.S. 213 (1983), that question has not been briefed or argued; and it is also within our authority, which we choose to exercise, to take the case as it comes to us, accepting the Court of Appeals' conclusion that probable cause was lacking under the prevailing legal standards. See this Court's Rule 21.1(a).

We have concluded that, in the Fourth Amendment context, the exclusionary rule can be modified somewhat without jeopardizing its ability to perform its intended functions. Accordingly, we reverse the judgment of the Court of Appeals.

II

Language in opinions of this Court and of individual Justices has sometimes implied that the exclusionary rule is a necessary corollary of the Fourth Amendment, Mapp v. [468 U.S. 897, 906] Ohio, 367 U.S. 643, 651, 655-657 (1961); Olmstead v. United States, 277 U.S. 438, 462-463 (1928), or that the rule is required by the conjunction of the Fourth and Fifth Amendments. Mapp v. Ohio, supra, at 661-662 (Black, J., concurring); Agnello v. United States, 269 U.S. 20, 33-34 (1925). These implications need not detain us long. The Fifth Amendment theory has not withstood critical analysis or the test of time, see Andresen v. Maryland, 427 U.S. 463 (1976), and the Fourth Amendment "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. 465, 486 (1976).

A

The Fourth Amendment contains no provision expressly precluding the use of evidence obtained in violation of its commands, and an examination of its origin and purposes makes clear that the use of fruits of a past unlawful search or seizure "work[s] no new Fourth Amendment wrong." United States v. Calandra, 414 U.S. 338, 354 (1974). The wrong condemned by the Amendment is "fully accomplished" by the unlawful search or seizure itself, ibid., and the exclusionary rule is neither intended nor able to "cure the invasion of the defendant's rights which he has already suffered." Stone v. Powell, supra, at 540 (WHITE, J., dissenting). The rule thus operates as "a judicially created remedy designed to safeguard Fourth Amendment rights generally through its deterrent effect, rather than a personal constitutional right of the party aggrieved." United States v. Calandra, supra, at 348.

Whether the exclusionary sanction is appropriately imposed in a particular case, our decisions make clear, is "an issue separate from the question whether the Fourth Amendment rights of the party seeking to invoke the rule were violated by police conduct." Illinois v. Gates, supra, at 223. Only the former question is currently before us, and it must [468 U.S. 897, 907] be resolved by weighing the costs and benefits of preventing the use in the prosecution's case in chief of inherently trustworthy tangible evidence obtained in reliance on a search warrant issued by a detached and neutral magistrate that ultimately is found to be defective.

The substantial social costs exacted by the exclusionary rule for the vindication of Fourth Amendment rights have long been a source of concern. "Our cases have consistently recognized that unbending application of the exclusionary sanction to enforce ideals of governmental rectitude would impede unacceptably the truth-finding functions of judge and jury." United States v. Payner, 447 U.S. 727, 734 (1980). An objectionable collateral consequence of this interference with the criminal justice system's truth-finding function is that some guilty defendants may go free or receive reduced sentences as a result of favorable plea bargains.6 Particularly [468 U.S. 897, 908] when law enforcement officers have acted in objective good faith or their transgressions have been minor, the magnitude of the benefit conferred on such guilty defendants offends basic concepts of the criminal justice system. Stone v. Powell, 428 U.S., at 490. Indiscriminate application of the exclusionary rule, therefore, may well "generat[e] disrespect for the law and administration of justice." Id., at 491. Accordingly, "[a]s with any remedial device, the application of the rule has been restricted to those areas where its remedial objectives are thought most efficaciously served." United States v. Calandra, supra, at 348; see Stone v. Powell, supra, at 486-487; United States v. Janis, 428 U.S. 433, 447 (1976).

B

Close attention to those remedial objectives has characterized our recent decisions concerning the scope of the Fourth Amendment exclusionary rule. The Court has, to be sure, not seriously questioned, "in the absence of a more efficacious sanction, the continued application of the rule to suppress evidence [468 U.S. 897, 909] from the [prosecution's] case where a Fourth Amendment violation has been substantial and deliberate. . . ." Franks v. Delaware, 438 U.S. 154, 171 (1978); Stone v. Powell, supra, at 492. Nevertheless, the balancing approach that has evolved in various contexts - including criminal trials - "forcefully suggest[s] that the exclusionary rule be more generally modified to permit the introduction of evidence obtained in the reasonable good-faith belief that a search or seizure was in accord with the Fourth Amendment." Illinois v. Gates, 462 U.S., at 255 (WHITE, J., concurring in judgment).

In Stone v. Powell, supra, the Court emphasized the costs of the exclusionary rule, expressed its view that limiting the circumstances under which Fourth Amendment claims could be raised in federal habeas corpus proceedings would not reduce the rule's deterrent effect, id., at 489-495, and held that a state prisoner who has been afforded a full and fair opportunity to litigate a Fourth Amendment claim may not obtain federal habeas relief on the ground that unlawfully obtained evidence had been introduced at his trial. Cf. Rose v. Mitchell, 443 U.S. 545, 560-563 (1979). Proposed extensions of the exclusionary rule to proceedings other than the criminal trial itself have been evaluated and rejected under the same analytic approach. In United States v. Calandra, for example, we declined to allow grand jury witnesses to refuse to answer questions based on evidence obtained from an unlawful search or seizure since "[a]ny incremental deterrent effect which might be achieved by extending the rule to grand jury proceedings is uncertain at best." 414 U.S., at 348. Similarly, in United States v. Janis, supra, we permitted the use in federal civil proceedings of evidence illegally seized by state officials since the likelihood of deterring police misconduct through such an extension of the exclusionary rule was insufficient to outweigh its substantial social costs. In so doing, we declared that, "[i]f . . . the exclusionary rule does not result in appreciable deterrence, then, clearly, its use in the instant situation is unwarranted." Id., at 454. [468 U.S. 897, 910]

As cases considering the use of unlawfully obtained evidence in criminal trials themselves make clear, it does not follow from the emphasis on the exclusionary rule's deterrent value that "anything which deters illegal searches is thereby commanded by the Fourth Amendment." Alderman v. United States, 394 U.S., at 174. In determining whether persons aggrieved solely by the introduction of damaging evidence unlawfully obtained from their co-conspirators or codefendants could seek suppression, for example, we found that the additional benefits of such an extension of the exclusionary rule would not outweigh its costs. Id., at 174-175. Standing to invoke the rule has thus been limited to cases in which the prosecution seeks to use the fruits of an illegal search or seizure against the victim of police misconduct. Rakas v. Illinois, 439 U.S. 128 (1978); Brown v. United States, 411 U.S. 223 (1973); Wong Sun v. United States, 371 U.S. 471, 491-492 (1963). Cf. United States v. Payner, 447 U.S. 727 (1980).

Even defendants with standing to challenge the introduction in their criminal trials of unlawfully obtained evidence cannot prevent every conceivable use of such evidence. Evidence obtained in violation of the Fourth Amendment and inadmissible in the prosecution's case in chief may be used to impeach a defendant's direct testimony. Walder v. United States, 347 U.S. 62 (1954). See also Oregon v. Hass, 420 U.S. 714 (1975); Harris v. New York, 401 U.S. 222 (1971). A similar assessment of the "incremental furthering" of the ends of the exclusionary rule led us to conclude in United States v. Havens, 446 U.S. 620, 627 (1980), that evidence inadmissible in the prosecution's case in chief or otherwise as substantive evidence of guilt may be used to impeach statements made by a defendant in response to "proper cross-examination reasonably suggested by the defendant's direct examination." Id., at 627-628.

When considering the use of evidence obtained in violation of the Fourth Amendment in the prosecution's case in chief, moreover, we have declined to adopt a per se or "but for" rule [468 U.S. 897, 911] that would render inadmissible any evidence that came to light through a chain of causation that began with an illegal arrest. Brown v. Illinois, 422 U.S. 590 (1975); Wong Sun v. United States, supra, at 487-488. We also have held that a witness' testimony may be admitted even when his identity was discovered in an unconstitutional search. United States v. Ceccolini, 435 U.S. 268 (1978). The perception underlying these decisions - that the connection between police misconduct and evidence of crime may be sufficiently attenuated to permit the use of that evidence at trial - is a product of considerations relating to the exclusionary rule and the constitutional principles it is designed to protect. Dunaway v. New York, 442 U.S. 200, 217-218 (1979); United States v. Ceccolini, supra, at 279.7 In short, the "dissipation of the taint" concept that the Court has applied in deciding whether exclusion is appropriate in a particular case "attempts to mark the point at which the detrimental consequences of illegal police action become so attenuated that the deterrent effect of the exclusionary rule no longer justifies its cost." Brown v. Illinois, supra, at 609 (POWELL, J., concurring in part). Not surprisingly in view of this purpose, an assessment of the flagrancy of the police misconduct constitutes an important step in the calculus. Dunaway v. New York, supra, at 218; Brown v. Illinois, supra, at 603-604.

The same attention to the purposes underlying the exclusionary rule also has characterized decisions not involving the scope of the rule itself. We have not required suppression of the fruits of a search incident to an arrest made in good-faith reliance on a substantive criminal statute that subsequently [468 U.S. 897, 912]is declared unconstitutional. Michigan v. DeFillippo, 443 U.S. 31 (1979).8 Similarly, although the Court has been unwilling to conclude that new Fourth Amendment principles are always to have only prospective effect, United States v. Johnson, 457 U.S. 537, 560 (1982),9 no Fourth Amendment decision marking a "clear break with the past" has been applied retroactively. See United States v. Peltier, 422 U.S. 531 (1975); Desist v. United States, 394 U.S. 244 (1969); Linkletter v. Walker, 381 U.S. 618 (1965).10 The propriety [468 U.S. 897, 913] of retroactive application of a newly announced Fourth Amendment principle, moreover, has been assessed largely in terms of the contribution retroactivity might make to the deterrence of police misconduct. United States v. Johnson, supra, at 560-561; United States v. Peltier, supra, at 536-539, 542.

As yet, we have not recognized any form of good-faith exception to the Fourth Amendment exclusionary rule.11 But the balancing approach that has evolved during the years of experience with the rule provides strong support for the modification currently urged upon us. As we discuss below, our evaluation of the costs and benefits of suppressing reliable physical evidence seized by officers reasonably relying on a warrant issued by a detached and neutral magistrate leads to the conclusion that such evidence should be admissible in the prosecution's case in chief.

III

A

Because a search warrant "provides the detached scrutiny of a neutral magistrate, which is a more reliable safeguard [468 U.S. 897, 914] against improper searches than the hurried judgment of a law enforcement officer `engaged in the often competitive enterprise of ferreting out crime,'" United States v. Chadwick, 433 U.S. 1, 9 (1977) (quoting Johnson v. United States, 333 U.S. 10, 14 (1948)), we have expressed a strong preference for warrants and declared that "in a doubtful or marginal case a search under a warrant may be sustainable where without one it would fall." United States v. Ventresca, 380 U.S. 102, 106 (1965). See Aguilar v. Texas, 378 U.S., at 111. Reasonable minds frequently may differ on the question whether a particular affidavit establishes probable cause, and we have thus concluded that the preference for warrants is most appropriately effectuated by according "great deference" to a magistrate's determination. Spinelli v. United States, 393 U.S., at 419. See Illinois v. Gates, 462 U.S., at 236; United States v. Ventresca, supra, at 108-109.

Deference to the magistrate, however, is not boundless. It is clear, first, that the deference accorded to a magistrate's finding of probable cause does not preclude inquiry into the knowing or reckless falsity of the affidavit on which that determination was based. Franks v. Delaware, 438 U.S. 154 (1978).12 Second, 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." Aguilar v. Texas, supra, at 111. See Illinois v. Gates, supra, at 239. A magistrate failing to "manifest that neutrality and detachment demanded of a judicial officer when presented with a warrant application" and who acts instead as "an adjunct law enforcement officer" cannot provide valid authorization for an otherwise unconstitutional search. Lo-Ji Sales, Inc. v. New York, 442 U.S. 319, 326-327 (1979). [468 U.S. 897, 915]

Third, 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." Illinois v. Gates, 462 U.S., at 239. "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." Ibid. See Aguilar v. Texas, supra, at 114-115; Giordenello v. United States, 357 U.S. 480 (1958); Nathanson v. United States, 290 U.S. 41 (1933).13 Even if the warrant application was supported by more than a "bare bones" affidavit, a reviewing court may properly conclude that, notwithstanding the deference that magistrates deserve, the warrant was invalid because the magistrate's probable-cause determination reflected an improper analysis of the totality of the circumstances, Illinois v. Gates, supra, at 238-239, or because the form of the warrant was improper in some respect.

Only in the first of these three situations, however, has the Court set forth a rationale for suppressing evidence obtained pursuant to a search warrant; in the other areas, it has simply excluded such evidence without considering whether [468 U.S. 897, 916] Fourth Amendment interests will be advanced. To the extent that proponents of exclusion rely on its behavioral effects on judges and magistrates in these areas, their reliance is misplaced. First, the exclusionary rule is designed to deter police misconduct rather than to punish the errors of judges and magistrates. Second, there exists no evidence suggesting that judges and magistrates are inclined to ignore or subvert the Fourth Amendment or that lawlessness among these actors requires application of the extreme sanction of exclusion.14

Third, and most important, we discern no basis, and are offered none, for believing that exclusion of evidence seized pursuant to a warrant will have a significant deterrent effect on the issuing judge or magistrate.15 Many of the factors [468 U.S. 897, 917] that indicate that the exclusionary rule cannot provide an effective "special" or "general" deterrent for individual offending law enforcement officers16 apply as well to judges or magistrates. And, to the extent that the rule is thought to operate as a "systemic" deterrent on a wider audience,17 it clearly can have no such effect on individuals empowered to issue search warrants. Judges and magistrates are not adjuncts to the law enforcement team; as neutral judicial officers, they have no stake in the outcome of particular criminal prosecutions. The threat of exclusion thus cannot be expected significantly to deter them. Imposition of the exclusionary sanction is not necessary meaningfully to inform judicial officers of their errors, and we cannot conclude that admitting evidence obtained pursuant to a warrant while at the same time declaring that the warrant was somehow defective will in any way 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.18 [468 U.S. 897, 918]

B

If exclusion of evidence obtained pursuant to a subsequently invalidated warrant is to have any deterrent effect, therefore, it must alter the behavior of individual law enforcement officers or the policies of their departments. One could argue that applying the exclusionary rule in cases where the police failed to demonstrate probable cause in the warrant application deters future inadequate presentations or "magistrate shopping" and thus promotes the ends of the Fourth Amendment. Suppressing evidence obtained pursuant to a technically defective warrant supported by probable cause also might encourage officers to scrutinize more closely the form of the warrant and to point out suspected judicial errors. We find such arguments speculative and conclude that suppression of evidence obtained pursuant to a warrant should be ordered only on a case-by-case basis and only in those unusual cases in which exclusion will further the purposes of the exclusionary rule.19

We have frequently questioned whether the exclusionary rule can have any deterrent effect when the offending officers acted in the objectively reasonable belief that their conduct did not violate the Fourth Amendment. "No empirical researcher, proponent or opponent of the rule, has yet been able to establish with any assurance whether the rule has a deterrent effect . . . ." United States v. Janis, 428 U.S., at 452, n. 22. But even assuming that the rule effectively [468 U.S. 897, 919] 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.

C

We conclude that the marginal or nonexistent benefits produced by suppressing evidence obtained in objectively reasonable reliance on a subsequently invalidated search warrant cannot justify the substantial costs of exclusion. We do not suggest, however, that exclusion is always inappropriate in cases where an officer has obtained a warrant and abided by its terms. "[S]earches pursuant to a warrant will rarely require any deep inquiry into reasonableness," Illinois v. Gates, 462 U.S., at 267 (WHITE, J., concurring in judgment), for "a warrant issued by a magistrate normally suffices to establish" that a law enforcement officer has "acted in good faith in conducting the search." United States v. Ross, 456 U.S. 798, 823, n. 32 (1982). Nevertheless, the officer's reliance on the magistrate's probable-cause determination and on the technical sufficiency of the warrant he issues must be objectively reasonable, cf. Harlow v. Fitzgerald, 457 U.S. 800, 815-819 (1982),23 and it is clear that in some circumstances [468 U.S. 897, 923] the officer 24 will have no reasonable grounds for believing that the warrant was properly issued.

Suppression therefore 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. Franks v. Delaware, 438 U.S. 154 (1978). The exception we recognize today will also not apply in cases where the issuing magistrate wholly abandoned his judicial role in the manner condemned in Lo-Ji Sales, Inc. v. New York, 442 U.S. 319 (1979); in such circumstances, no reasonably well trained officer should rely on the warrant. 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." Brown v. Illinois, 422 U.S., at 610-611 (POWELL, J., concurring in part); see Illinois v. Gates, supra, at 263-264 (WHITE, J., concurring in judgment). 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. Cf. Massachusetts v. Sheppard, post, at 988-991.

In so limiting the suppression remedy, we leave untouched the probable-cause standard and the various requirements for a valid warrant. Other objections to the modification of [468 U.S. 897, 924] the Fourth Amendment exclusionary rule we consider to be insubstantial. The good-faith exception for searches conducted pursuant to warrants is not intended to signal our unwillingness strictly to enforce the requirements of the Fourth Amendment, and we do not believe that it will have this effect. As we have already suggested, the good-faith exception, turning as it does on objective reasonableness, should not be difficult to apply in practice. When officers have acted pursuant to a warrant, the prosecution should ordinarily be able to establish objective good faith without a substantial expenditure of judicial time.

Nor are we persuaded that application of a good-faith exception to searches conducted pursuant to warrants will preclude review of the constitutionality of the search or seizure, deny needed guidance from the courts, or freeze Fourth Amendment law in its present state.25 There is no need for courts to adopt the inflexible practice of always deciding whether the officers' conduct manifested objective good faith before turning to the question whether the Fourth Amendment has been violated. Defendants seeking suppression of the fruits of allegedly unconstitutional searches or seizures undoubtedly raise live controversies which Art. III empowers federal courts to adjudicate. As cases addressing questions of good-faith immunity under 42 U.S.C. 1983, compare O'Connor v. Donaldson, 422 U.S. 563 (1975), with Procunier v. Navarette, 434 U.S. 555, 566, n. 14 (1978), and cases involving the harmless-error doctrine, compare Milton v. Wainwright, 407 U.S. 371, 372 (1972), with Coleman v. Alabama, 399 U.S. 1 (1970), make clear, courts have considerable [468 U.S. 897, 925] discretion in conforming their decisionmaking processes to the exigencies of particular cases.

If the resolution of a particular Fourth Amendment question is necessary to guide future action by law enforcement officers and magistrates, nothing will prevent reviewing courts from deciding that question before turning to the good-faith issue.26 Indeed, it frequently will be difficult to determine whether the officers acted reasonably without resolving the Fourth Amendment issue. Even if the Fourth Amendment question is not one of broad import, reviewing courts could decide in particular cases that magistrates under their supervision need to be informed of their errors and so evaluate the officers' good faith only after finding a violation. In other circumstances, those courts could reject suppression motions posing no important Fourth Amendment questions by turning immediately to a consideration of the officers' good faith. We have no reason to believe that our Fourth Amendment jurisprudence would suffer by allowing reviewing courts to exercise an informed discretion in making this choice.

IV

When the principles we have enunciated today are applied to the facts of this case, it is apparent that the judgment of the Court of Appeals cannot stand. The Court of Appeals applied the prevailing legal standards to Officer Rombach's warrant application and concluded that the application could not support the magistrate's probable-cause determination. In so doing, the court clearly informed the magistrate that he [468 U.S. 897, 926] had erred in issuing the challenged warrant. This aspect of the court's judgment is not under attack in this proceeding.

Having determined that the warrant should not have issued, the Court of Appeals understandably declined to adopt a modification of the Fourth Amendment exclusionary rule that this Court had not previously sanctioned. Although the modification finds strong support in our previous cases, the Court of Appeals' commendable self-restraint is not to be criticized. We have now reexamined the purposes of the exclusionary rule and the propriety of its application in cases where officers have relied on a subsequently invalidated search warrant. Our conclusion is that the rule's purposes will only rarely be served by applying it in such circumstances.

In the absence of an allegation that the magistrate abandoned his detached and neutral role, suppression is appropriate only if the officers were dishonest or reckless in preparing their affidavit or could not have harbored an objectively reasonable belief in the existence of probable cause. Only respondent Leon has contended that no reasonably well trained police officer could have believed that there existed probable cause to search his house; significantly, the other respondents advance no comparable argument. Officer Rombach's application for a warrant clearly was supported by much more than a "bare bones" affidavit. The affidavit related the results of an extensive investigation and, as the opinions of the divided panel of the Court of Appeals make clear, provided evidence sufficient to create disagreement among thoughtful and competent judges as to the existence of probable cause. Under these circumstances, the officers' reliance on the magistrate's determination of probable cause was objectively reasonable, and application of the extreme sanction of exclusion is inappropriate.

[Footnote 1] Respondent Leon moved to suppress the evidence found on his person at the time of his arrest and the evidence seized from his residence at 716 South Sunset Canyon. Respondent Stewart's motion covered the fruits of searches of her residence at 620 Price Drive and the condominium at 7902 Via Magdalena and statements she made during the search of her residence. Respondent Sanchez sought to suppress the evidence discovered during the search of his residence at 620 Price Drive and statements he made shortly thereafter. He also joined Stewart's motion to suppress evidence seized from the condominium. Respondent Del Castillo apparently sought to suppress all of the evidence seized in the searches. App. 78-80. The respondents also moved to suppress evidence seized in the searches of their automobiles.

[Footnote 6] Researchers have only recently begun to study extensively the effects of the exclusionary rule on the disposition of felony arrests. One study suggests that the rule results in the nonprosecution or nonconviction of between 0.6% and 2.35% of individuals arrested for felonies. Davies, A Hard Look at What We Know (and Still Need to Learn) About the "Costs" of the Exclusionary Rule: The NIJ Study and Other Studies of "Lost" Arrests, 1983 A. B. F. Res. J. 611, 621. The estimates are higher for particular crimes the prosecution of which depends heavily on physical evidence. Thus, the cumulative loss due to nonprosecution or nonconviction of individuals arrested on felony drug charges is probably in the range of 2.8% to 7.1%. Id., at 680. Davies' analysis of California data suggests that screening by police and prosecutors results in the release because of illegal searches or seizures of as many as 1.4% of all felony arrestees, id., at 650, that 0.9% of felony arrestees are released, because of illegal searches or seizures, at the preliminary hearing or after trial, id., at 653, and that roughly 0.05% of all felony arrestees benefit from reversals on appeal because of illegal searches. Id., at 654. See also K. Brosi, A Cross-City Comparison of Felony Case Processing 16, 18-19 (1979); U.S. General Accounting Office, Report of the Comptroller General of the United States, Impact of the Exclusionary Rule on Federal Criminal Prosecutions 10-11, 14 (1979); F. Feeney, F. Dill, & A. Weir, Arrests Without Convictions: How Often They Occur and Why 203-206 (National Institute of Justice [468 U.S. 897, 908]; National Institute of Justice, The Effects of the Exclusionary Rule: A Study in California 1-2 (1982); Nardulli, The Societal Cost of the Exclusionary Rule: An Empirical Assessment, 1983 A. B. F. Res. J. 585, 600. The exclusionary rule also has been found to affect the plea-bargaining process. S. Schlesinger, Exclusionary Injustice: The Problem of Illegally Obtained Evidence 63 (1977). But see Davies, supra, at 668-669; Nardulli, supra, at 604-606.

Many of these researchers have concluded that the impact of the exclusionary rule is insubstantial, but the small percentages with which they deal mask a large absolute number of felons who are released because the cases against them were based in part on illegal searches or seizures. "[A]ny rule of evidence that denies the jury access to clearly probative and reliable evidence must bear a heavy burden of justification, and must be carefully limited to the circumstances in which it will pay its way by deterring official unlawlessness." Illinois v. Gates, 462 U.S., at 257-258 (WHITE, J., concurring in judgment). Because we find that the rule can have no substantial deterrent effect in the sorts of situations under consideration in this case, see infra, at 916-921, we conclude that it cannot pay its way in those situations.

[Footnote 7] "Brown's focus on `the causal connection between the illegality and the confession' reflected the two policies behind the use of the exclusionary rule to effectuate the Fourth Amendment. Where there is a close causal connection between the illegal seizure and the confession, not only is exclusion of the evidence more likely to deter similar police misconduct in the future, but use of the evidence is more likely to compromise the integrity of the courts." Dunaway v. New York, 442 U.S., at 217-218 (citation omitted).

[Footnote 8] We have held, however, that the exclusionary rule requires suppression of evidence obtained in searches carried out pursuant to statutes, not yet declared unconstitutional, purporting to authorize searches and seizures without probable cause or search warrants. See, e. g., Ybarra v. Illinois, 444 U.S. 85 (1979); Torres v. Puerto Rico, 442 U.S. 465 (1979); Almeida-Sanchez v. United States, 413 U.S. 266 (1973); Sibron v. New York, 392 U.S. 40 (1968); Berger v. New York, 388 U.S. 41 (1967). "Those decisions involved statutes which, by their own terms, authorized searches under circumstances which did not satisfy the traditional warrant and probable-cause requirements of the Fourth Amendment." Michigan v. DeFillippo, 443 U.S., at 39. The substantive Fourth Amendment principles announced in those cases are fully consistent with our holding here.

[Footnote 9] The Court held in United States v. Johnson, that a construction of the Fourth Amendment that did not constitute a "clear break with the past" is to be applied to all convictions not yet final when the decision was handed down. The limited holding, see 457 U.S., at 562, turned in part on the Court's judgment that "[f]ailure to accord any retroactive effect to Fourth Amendment rulings would `encourage police or other courts to disregard the plain purport of our decisions and to adopt a let's-wait-until-it's-decided approach.'" Id., at 561 (emphasis in original) (quoting Desist v. United States, 394 U.S. 244, 277 (1969) (Fortas, J., dissenting)). Contrary to respondents' assertions, nothing in Johnson precludes adoption of a good-faith exception tailored to situations in which the police have reasonably relied on a warrant issued by a detached and neutral magistrate but later found to be defective.

[Footnote 12] Indeed, "it would be an unthinkable imposition upon [the magistrate's] authority if a warrant affidavit, revealed after the fact to contain a deliberately or recklessly false statement, were to stand beyond impeachment." 438 U.S., at 165.

[Footnote 14] Although there are assertions that some magistrates become rubber stamps for the police and others may be unable effectively to screen police conduct, see, e. g., 2 W. LaFave, Search and Seizure 4.1 (1978); Kamisar, Does (Did) (Should) The Exclusionary Rule Rest on a "Principled Basis" Rather than an "Empirical Proposition"?, 16 Creighton L. Rev. 565, 569-571 (1983); Schroeder, Deterring Fourth Amendment Violations: Alternatives to the Exclusionary Rule, 69 Geo. L. J. 1361, 1412 (1981), we are not convinced that this is a problem of major proportions. See L. Tiffany, D. McIntyre, & D. Rotenberg, Detection of Crime 119 (1967); Israel, Criminal Procedure, the Burger Court, and the Legacy of the Warren Court, 75 Mich. L. Rev. 1319, 1414, n. 396 (1977); P. Johnson, New Approaches to Enforcing the Fourth Amendment 8-10 (Working Paper, Sept. 1978), quoted in Y. Kamisar, W. LaFave, & J. Israel, Modern Criminal Procedure 229-230 (5th ed. 1980); R. Van Duizend, L. Sutton, & C. Carter, The Search Warrant Process, ch. 7 (Review Draft, National Center for State Courts, 1983).

[Footnote 16] See, e. g., Stone v. Powell, 428 U.S., at 498 (BURGER, C. J., concurring); Oaks, Studying the Exclusionary Rule in Search and Seizure, 37 U. Chi. L. Rev. 665, 709-710 (1970).

[Footnote 17] See, e. g., Dunaway v. New York, 442 U.S. 220, 221 (1979) (STEVENS, J., concurring); Mertens & Wasserstrom, The Good Faith Exception to the Exclusionary Rule: Deregulating the Police and Derailing the Law, 70 Geo. L. J. 365, 399-401 (1981).

[Footnote 18] Limiting the application of the exclusionary sanction may well increase the care with which magistrates scrutinize warrant applications. We doubt that magistrates are more desirous of avoiding the exclusion of evidence obtained pursuant to warrants they have issued than of avoiding invasions of privacy.

Federal magistrates, moreover, are subject to the direct supervision of district courts. They may be removed for "incompetency, misconduct, neglect of duty, or physical or mental disability." 28 U.S.C. 631(i). If a magistrate serves merely as a "rubber stamp" for the police or is [468 U.S. 897, 918] unable to exercise mature judgment, closer supervision or removal provides a more effective remedy than the exclusionary rule.

[Footnote 19] Our discussion of the deterrent effect of excluding evidence obtained in reasonable reliance on a subsequently invalidated warrant assumes, of course, that the officers properly executed the warrant and searched only those places and for those objects that it was reasonable to believe were covered by the warrant. Cf. Massachusetts v. Sheppard, post, at 989, n. 6 ("[I]t was not unreasonable for the police in this case to rely on the judge's assurances that the warrant authorized the search they had requested").

[Footnote 23] In Harlow, we eliminated the subjective component of the qualified immunity public officials enjoy in suits seeking damages for alleged deprivations of constitutional rights. The situations are not perfectly analogous, but we also eschew inquiries into the subjective beliefs of law enforcement officers who seize evidence pursuant to a subsequently invalidated warrant. Although we have suggested that, "[o]n occasion, the motive with which the officer conducts an illegal search may have some relevance in determining the propriety of applying the exclusionary rule." Scott v. United States, 436 U.S. 128, 139, n. 13 (1978), we believe that "sending 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). Accordingly, our good-faith inquiry is confined to the objectively ascertainable question whether a reasonably well trained officer would have known that the search was illegal despite the magistrate's authorization. In making this determination, all of the circumstances - [468 U.S. 897, 923] including whether the warrant application had previously been rejected by a different magistrate - may be considered.

[Footnote 24] References to "officer" throughout this opinion should not be read too narrowly. It is necessary to consider the objective reasonableness, not only of the officers who eventually executed a warrant, but also of the officers who originally obtained it or who provided information material to the probable-cause determination. Nothing in our opinion suggests, for example, that an officer could obtain a warrant on the basis of a "bare bones" affidavit and then rely on colleagues who are ignorant of the circumstances under which the warrant was obtained to conduct the search. See Whiteley v. Warden, 401 U.S. 560, 568 (1971).

[Footnote 25] The argument that defendants will lose their incentive to litigate meritorious Fourth Amendment claims as a result of the good-faith exception we adopt today is unpersuasive. Although the exception might discourage presentation of insubstantial suppression motions, the magnitude of the benefit conferred on defendants by a successful motion makes it unlikely that litigation of colorable claims will be substantially diminished.

[Footnote 26] It has been suggested, in fact, that "the recognition of a `penumbral zone,' within which an inadvertent mistake would not call for exclusion, . . . will make it less tempting for judges to bend fourth amendment standards to avoid releasing a possibly dangerous criminal because of a minor and unintentional miscalculation by the police." Schroeder, supra n. 14, at 1420-1421 (footnote omitted); see Ashdown, Good Faith, the Exclusionary Remedy, and Rule-Oriented Adjudication in the Criminal Process, 24 Wm. & Mary L. Rev. 335, 383-384 (1983). [468 U.S. 897, 927]

JUSTICE BLACKMUN, concurring.

The Court today holds that evidence obtained in violation of the Fourth Amendment by officers acting in objectively reasonable reliance on a search warrant issued by a neutral and detached magistrate need not be excluded, as a matter of federal law, from the case in chief of federal and state criminal prosecutions. In so doing, the Court writes another chapter in the volume of Fourth Amendment law opened by Weeks v. United States, 232 U.S. 383 (1914). I join the Court's opinion in this case and the one in Massachusetts v. Sheppard, post, p. 981, because I believe that the rule announced today advances the legitimate interests of the criminal justice system without sacrificing the individual rights protected by the Fourth Amendment. I write separately, however, to underscore what I regard as the unavoidably provisional nature of today's decisions.

As the Court's opinion in this case makes clear, the Court has narrowed the scope of the exclusionary rule because of an empirical judgment that the rule has little appreciable effect in cases where officers act in objectively reasonable reliance on search warrants. See ante, at 918-921. Because I share the view that the exclusionary rule is not a constitutionally compelled corollary of the Fourth Amendment itself, see ante, at 905-906, I see no way to avoid making an empirical judgment of this sort, and I am satisfied that the Court has made the correct one on the information before it. Like all courts, we face institutional limitations on our ability to gather information about "legislative facts," and the exclusionary rule itself has exacerbated the shortage of hard data concerning the behavior of police officers in the absence of such a rule. See United States v. Janis, 428 U.S. 433, 448-453 (1976). Nonetheless, we cannot escape the responsibility to decide the question before us, however imperfect our information may be, and I am prepared to join the Court on the information now at hand. [468 U.S. 897, 928]

What must be stressed, however, is that any empirical judgment about the effect of the exclusionary rule in a particular class of cases necessarily is a provisional one. By their very nature, the assumptions on which we proceed today cannot be cast in stone. To the contrary, they now will be tested in the real world of state and federal law enforcement, and this Court will attend to the results. If it should emerge from experience that, contrary to our expectations, the good-faith exception to the exclusionary rule results in a material change in police compliance with the Fourth Amendment, we shall have to reconsider what we have undertaken here. The logic of a decision that rests on untested predictions about police conduct demands no less.

If a single principle may be drawn from this Court's exclusionary rule decisions, from Weeks through Mapp v. Ohio, 367 U.S. 643 (1961), to the decisions handed down today, it is that the scope of the exclusionary rule is subject to change in light of changing judicial understanding about the effects of the rule outside the confines of the courtroom. It is incumbent on the Nation's law enforcement officers, who must continue to observe the Fourth Amendment in the wake of today's decisions, to recognize the double-edged nature of that principle.

JUSTICE BRENNAN, with whom JUSTICE MARSHALL joins, dissenting.*

Ten years ago in United States v. Calandra, 414 U.S. 338 (1974), I expressed the fear that the Court's decision "may signal that a majority of my colleagues have positioned themselves to reopen the door [to evidence secured by official lawlessness] still further and abandon altogether the exclusionary rule in search-and-seizure cases." Id., at 365 (dissenting opinion). Since then, in case after case, I have witnessed the Court's gradual but determined strangulation [468 U.S. 897, 929] of the rule.1 It now appears that the Court's victory over the Fourth Amendment is complete. That today's decisions represent the piece de resistance of the Court's past efforts cannot be doubted, for today the Court sanctions the use in the prosecution's case in chief of illegally obtained evidence against the individual whose rights have been violated - a result that had previously been thought to be foreclosed.

The Court seeks to justify this result on the ground that the "costs" of adhering to the exclusionary rule in cases like those before us exceed the "benefits." But the language of deterrence and of cost/benefit analysis, if used indiscriminately, can have a narcotic effect. It creates an illusion of technical precision and ineluctability. It suggests that not only constitutional principle but also empirical data support the majority's result. When the Court's analysis is examined carefully, however, it is clear that we have not been treated to an honest assessment of the merits of the exclusionary rule, but have instead been drawn into a curious world where the "costs" of excluding illegally obtained evidence loom to exaggerated heights and where the "benefits" of such exclusion are made to disappear with a mere wave of the hand.

A proper understanding of the broad purposes sought to be served by the Fourth Amendment demonstrates that the principles embodied in the exclusionary rule rest upon a far firmer constitutional foundation than the shifting sands of the Court's deterrence rationale. But even if I were to accept the Court's chosen method of analyzing the question posed by these cases, I would still conclude that the Court's decision cannot be justified.

I

The Court holds that physical evidence seized by police officers reasonably relying upon a warrant issued by a detached [468 U.S. 897, 931] and neutral magistrate is admissible in the prosecution's case in chief, even though a reviewing court has subsequently determined either that the warrant was defective. No. 82-963, or that those officers failed to demonstrate when applying for the warrant that there was probable cause to conduct the search, No. 82-1771. I have no doubt that these decisions will prove in time to have been a grave mistake. But, as troubling and important as today's new doctrine may be for the administration of criminal justice in this country, the mode of analysis used to generate that doctrine also requires critical examination, for it may prove in the long run to pose the greater threat to our civil liberties.

A

At bottom, the Court's decision turns on the proposition that the exclusionary rule is merely a "`judicially created remedy designed to safeguard Fourth Amendment rights generally through its deterrent effect, rather than a personal constitutional right.'" Ante, at 906, quoting United States v. Calandra, 414 U.S., at 348. The germ of that idea is found in Wolf v. Colorado, 338 U.S. 25 (1949), and although I had thought that such a narrow conception of the rule had been forever put to rest by our decision in Mapp v. Ohio, 367 U.S. 643 (1961), it has been revived by the present Court and reaches full flower with today's decision. The essence of this view, as expressed initially in the Calandra opinion and as reiterated today, is that the sole "purpose of the Fourth Amendment is to prevent unreasonable governmental intrusions into the privacy of one's person, house, papers, or effects. The wrong condemned is the unjustified governmental invasion of these areas of an individual's life. That wrong . . . is fully accomplished by the original search without probable cause." 414 U.S., at 354 (emphasis added); see also ante, at 906. This reading of the Amendment implies that its proscriptions are directed solely at those government agents who may actually invade an individual's constitutionally [468 U.S. 897, 932] protected privacy. The courts are not subject to any direct constitutional duty to exclude illegally obtained evidence, because the question of the admissibility of such evidence is not addressed by the Amendment. This view of the scope of the Amendment relegates the judiciary to the periphery. Because the only constitutionally cognizable injury has already been "fully accomplished" by the police by the time a case comes before the courts, the Constitution is not itself violated if the judge decides to admit the tainted evidence. Indeed, the most the judge can do is wring his hands and hope that perhaps by excluding such evidence he can deter future transgressions by the police.

Such a reading appears plausible, because, as critics of the exclusionary rule never tire of repeating,2 the Fourth Amendment makes no express provision for the exclusion of evidence secured in violation of its commands. A short answer to this claim, of course, is that many of the Constitution's most vital imperatives are stated in general terms and the task of giving meaning of these precepts is therefore left to subsequent judicial decisionmaking in the context of concrete cases. The nature of our Constitution, as Chief Justice Marshall long ago explained, "requires that only its great outlines should be marked, its important objects designated, and the minor ingredients which compose those objects be deduced from the nature of the objects themselves." McCulloch v. Maryland, 4 Wheat. 316, 407 (1819).

A more direct answer may be supplied by recognizing that the Amendment, like other provisions of the Bill of Rights, restrains the power of the government as a whole; it does not specify only a particular agency and exempt all others. The judiciary is responsible, no less than the executive, for ensuring that constitutional rights are respected. [468 U.S. 897, 933]

When that fact is kept in mind, the role of the courts and their possible involvement in the concerns of the Fourth Amendment comes into sharper focus. Because seizures are executed principally to secure evidence, and because such evidence generally has utility in our legal system only in the context of a trial supervised by a judge, it is apparent that the admission of illegally obtained evidence implicates the same constitutional concerns as the initial seizure of that evidence. Indeed, by admitting unlawfully seized evidence, the judiciary becomes a part of what is in fact a single governmental action prohibited by the terms of the Amendment.3 Once that connection between the evidence-gathering role of the police and the evidence-admitting function of the courts is acknowledged, the plausibility of the Court's interpretation becomes more suspect. Certainly nothing in the language or history of the Fourth Amendment suggests that a recognition of this evidentiary link between the police and the courts was meant to be foreclosed.4 It is difficult to give any meaning [468 U.S. 897, 934] at all to the limitations imposed by the Amendment if they are read to proscribe only certain conduct by the police but to allow other agents of the same government to take advantage of evidence secured by the police in violation of its requirements.5 The Amendment therefore must be read to condemn not only the initial unconstitutional invasion of privacy - which is done, after all, for the purpose of securing evidence - but also the subsequent use of any evidence so obtained. [468 U.S. 897, 935]

The Court evades this principle by drawing an artificial line between the constitutional rights and responsibilities that are engaged by actions of the police and those that are engaged when a defendant appears before the courts. According to the Court, the substantive protections of the Fourth Amendment are wholly exhausted at the moment when police unlawfully invade an individual's privacy and thus no substantive force remains to those protections at the time of trial when the government seeks to use evidence obtained by the police.

I submit that such a crabbed reading of the Fourth Amendment casts aside the teaching of those Justices who first formulated the exclusionary rule, and rests ultimately on an impoverished understanding of judicial responsibility in our constitutional scheme. For my part, "[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures" comprises a personal right to exclude all evidence secured by means of unreasonable searches and seizures. The right to be free from the initial invasion of privacy and the right of exclusion are coordinate components of the central embracing right to be free from unreasonable searches and seizures.

B

From the foregoing, it is clear why the question whether the exclusion of evidence would deter future police misconduct was never considered a relevant concern in the early cases from Weeks to Olmstead.6 In those formative decisions, the Court plainly understood that the exclusion of illegally obtained evidence was compelled not by judicially fashioned [468 U.S. 897, 939] remedial purposes, but rather by a direct constitutional command. A new phase in the history of the rule, however, opened with the Court's decision in Wolf v. Colorado, 338 U.S. 25 (1949). Although that decision held that the security of one's person and privacy protected by the Fourth Amendment was "implicit in `the concept of ordered liberty' and as such enforceable against the States through the Due Process Clause" of the Fourteenth Amendment, id., at 27-28, quoting Palko v. Connecticut, 302 U.S. 319, 325 (1937), the Court went on, in what can only be regarded as a tour de force of constitutional obfuscation, to say that the "ways of enforcing such a basic right raise questions of a different order," 338 U.S., at 28. Notwithstanding the force of the Weeks doctrine that the Fourth Amendment required exclusion, a state court was free to admit illegally seized evidence, according to the Court in Wolf, so long as the State had devised some other "effective" means of vindicating a defendant's Fourth Amendment rights. 338 U.S., at 31.

Twelve years later, in Mapp v. Ohio, 367 U.S. 643 (1961), however, the Court restored the original understanding of the Weeks case by overruling the holding of Wolf and repudiating its rationale. Although in the course of reaching this conclusion the Court in Mapp responded at certain points to the question, first raised in Wolf, of whether the exclusionary rule was an "effective" remedy compared to alternative means of enforcing the right, see 367 U.S., at 651-653, it nevertheless expressly held that "all evidence obtained by searches and seizures in violation of the Constitution is, by that same authority, inadmissible in a state court." Id., at 655 (emphasis added). In the Court's view, the exclusionary rule was not one among a range of options to be selected at the discretion of judges; it was "an essential part of both the Fourth and Fourteenth Amendments." Id., at 657. Rejection of the Wolf approach was constitutionally required, the Court explained, because "the admission of the new constitutional right by Wolf could not consistently tolerate denial of [468 U.S. 897, 940] its most important constitutional privilege, namely, the exclusion of the evidence which an accused had been forced to give by reason of the unlawful seizure. To hold otherwise is to grant the right but in reality to withhold its privilege and enjoyment." 367 U.S., at 656. Indeed, no other explanation suffices to account for the Court's holding in Mapp, since the only possible predicate for the Court's conclusion that the States were bound by the Fourteenth Amendment to honor the Weeks doctrine is that the exclusionary rule was "part and parcel of the Fourth Amendment's limitation upon [governmental] encroachment of individual privacy." 367 U.S., at 651.7

Despite this clear pronouncement, however, the Court since Calandra has gradually pressed the deterrence rationale for the rule back to center stage. See, e. g., United States v. Peltier, 422 U.S. 531 (1975); United States v. Janis, 428 U.S. 433 (1976); Stone v. Powell, 428 U.S. 465 (1976). The various arguments advanced by the Court in this campaign have only strengthened my conviction that the deterrence theory is both misguided and unworkable. First, [468 U.S. 897, 941] the Court has frequently bewailed the "cost" of excluding reliable evidence. In large part, this criticism rests upon a refusal to acknowledge the function of the Fourth Amendment itself. If nothing else, the Amendment plainly operates to disable the government from gathering information and securing evidence in certain ways. In practical terms, of course, this restriction of official power means that some incriminating evidence inevitably will go undetected if the government obeys these constitutional restraints. It is the loss of that evidence that is the "price" our society pays for enjoying the freedom and privacy safeguarded by the Fourth Amendment. Thus, some criminals will go free not, in Justice (then Judge) Cardozo's misleading epigram, "because the constable has blundered, " People v. Defore, 242 N. Y. 13, 21, 150 N. E. 585, 587 (1926), but rather because official compliance with Fourth Amendment requirements makes it more difficult to catch criminals. Understood in this way, the Amendment directly contemplates that some reliable and incriminating evidence will be lost to the government; therefore, it is not the exclusionary rule, but the Amendment itself that has imposed this cost. 8 [468 U.S. 897, 942]

In addition, the Court's decisions over the past decade have made plain that the entire enterprise of attempting to assess the benefits and costs of the exclusionary rule in various contexts is a virtually impossible task for the judiciary to perform honestly or accurately. Although the Court's language in those cases suggests that some specific empirical basis may support its analyses, the reality is that the Court's opinions represent inherently unstable compounds of intuition, hunches, and occasional pieces of partial and often inconclusive data. In Calandra, for example, the Court, in considering whether the exclusionary rule should apply in grand jury proceedings, had before it no concrete evidence whatever concerning the impact that application of the rule in such proceedings would have either in terms of the long-term costs or the expected benefits. To the extent empirical data are available regarding the general costs and benefits of the exclusionary rule, such data have shown, on the one hand, as the Court acknowledges today, that the costs are not as substantial as critics have asserted in the past, see ante, at 907-908, n. 6, and, on the other hand, that while the exclusionary rule may well have certain deterrent effects, it is extremely difficult to determine with any degree of precision whether the incidence of unlawful conduct by police is now lower than it was prior to Mapp. See United States v. Janis, 428 U.S., at 449-453, and n. 22; Stone v. Powell, 428 U.S., at 492, n. 32.9 The [468 U.S. 897, 943] Court has sought to turn this uncertainty to its advantage by casting the burden of proof upon proponents of the rule, see, e. g., United States v. Janis, supra, at 453-454. "Obviously," however, "the assignment of the burden of proof on an issue where evidence does not exist and cannot be obtained is outcome determinative. [The] assignment of the burden is merely a way of announcing a predetermined conclusion."10

By remaining within its redoubt of empiricism and by basing the rule solely on the deterrence rationale, the Court has robbed the rule of legitimacy. A doctrine that is explained as if it were an empirical proposition but for which there is only limited empirical support is both inherently unstable and an easy mark for critics. The extent of this Court's fidelity to Fourth Amendment requirements, however, should not turn on such statistical uncertainties. I share the view, expressed by Justice Stewart for the Court in Faretta v. California, 422 U.S. 806 (1975), that "[p]ersonal liberties are not rooted in the law of averages." Id., at 834. Rather than seeking to give effect to the liberties secured by the Fourth Amendment through guesswork about deterrence, the Court should restore to its proper place the principle framed 70 years ago in Weeks that an individual whose privacy has been invaded in violation of the Fourth Amendment has a right grounded in that Amendment to prevent the government from subsequently making use of any evidence so obtained. [468 U.S. 897, 944]

II

Application of that principle clearly requires affirmance in the two cases decided today. In the first, United States v. Leon, No. 82-1771, it is conceded by the Government and accepted by the Court that the affidavit filed by the police officers in support of their application for a search warrant failed to provide a sufficient basis on which a neutral and detached magistrate could conclude that there was probable cause to issue the warrant. Specifically, it is conceded that the officers' application for a warrant was based in part on information supplied by a confidential informant of unproven reliability that was over five months old by the time it was relayed to the police. Although the police conducted an independent investigation on the basis of this tip, both the District Court and the Court of Appeals concluded that the additional information gathered by the officers failed to corroborate the details of the informant's tip and was "as consistent with innocence as . . . with guilt." App. to Pet. for Cert. 10a. The warrant, therefore, should never have issued. Stripped of the authority of the warrant, the conduct of these officers was plainly unconstitutional - it amounted to nothing less than a naked invasion of the privacy of respondents' homes without the requisite justification demanded by the Fourth Amendment. In order to restore the Government to the position it would have occupied had this unconstitutional search not occurred, therefore, it was necessary that the evidence be suppressed. As we said in Coolidge v. New Hampshire, 403 U.S. 443 (1971), the Warrant Clause is not "an inconvenience to be somehow `weighed' against the claims of police efficiency. It is, or should be, an important working part of our machinery of government, operating as a matter of course to check the `well-intentioned but mistakenly over-zealous executive officers' who are part of any system of law enforcement." Id., at 481 (footnote omitted).

A close examination of the facts of this case reveals that this is neither an extraordinary nor indeed a very costly step. [468 U.S. 897, 945] The warrant had authorized a search for cocaine, methaqualone tablets, and miscellaneous narcotics paraphernalia at several locations: a condominium at 7902 Via Magdalena in Los Angeles; a residence at 620 Price Drive in Burbank; a residence at 716 South Sunset Canyon in Burbank; and four automobiles owned respectively by respondents Leon, Sanchez, Stewart, and Del Castillo. App. 31-33. Pursuant to this warrant, the officers seized approximately four pounds of cocaine and over 1,000 methaqualone tablets from the Via Magdalena condominium, nearly one pound of cocaine from the Sunset Canyon residence, about an ounce of cocaine from the Price Drive residence, and certain paraphernalia from Del Castillo's and Stewart's automobiles. On the basis of this and other evidence, the four respondents were charged with violating 21 U.S.C. 846 for conspiring to possess and distribute cocaine, and 841(a)(1) for possessing methaqualone and cocaine with intent to distribute. The indictment specifically alleged that respondents had maintained the Via Magdalena condominium as a storage area for controlled substances which they distributed to prospective purchasers. App. 27-28.

At the suppression hearing, the District Court determined that none of the respondents had a sufficient expectation of privacy to contest the search of the Via Magdalena condominium, that respondents Stewart and Sanchez could challenge the search of their home at Price Drive, that respondent Leon was entitled to challenge the search of his home at Sunset Canyon, and that respondents Del Castillo and Stewart could contest the search of their cars. Given its finding that probable cause to issue the warrant was lacking, the District Court ruled that the evidence from the Price Drive residence could not be used against respondents Stewart and Sanchez, that evidence from the Sunset Canyon residence could not be used against Leon, and that evidence obtained from both Del Castillo's and Stewart's automobiles could not be used against them. App. to Pet. for Cert. 10a-13a. [468 U.S. 897, 946]

The tenor of the Court's opinion suggests that this order somehow imposed a grave and presumably unjustifiable cost on society. Such a suggestion, however, is a gross exaggeration. Since the indictment focused upon a conspiracy among all respondents to use the Via Magdalena condominium as a storage area for controlled substances, and since the bulk of the evidence seized was from that condominium and was plainly admissible under the District Court's order, the Government would clearly still be able to present a strong case to the jury following the court's suppression order. I emphasize these details not to suggest how the Government's case would fare before the jury but rather to clarify a point that is lost in the Court's rhetorical excesses over the costs of the exclusionary rule - namely, that the suppression of evidence will certainly tend to weaken the Government's position but it will rarely force the Government to abandon a prosecution. Cf. infra, at 950-951, and n. 11. In my view, a doctrine that preserves intact the constitutional rights of the accused, and, at the same time, is sufficiently limited to permit society's legitimate and pressing interest in criminal law enforcement to be served should not be so recklessly discarded. It is a doctrine that gives life to the "very heart of the Fourth Amendment directive: that . . . a governmental search and seizure should represent both the efforts of the officer to gather evidence of wrongful acts and the judgment of the magistrate that the collected evidence is sufficient to justify invasion of a citizen's private premises." United States v. United States District Court, 407 U.S. 297, 316 (1972).

In the second case before the Court, Massachusetts v. Sheppard, No. 82-963, the State concedes and the Court accepts that the warrant issued to search respondent's home completely failed to state with particularity the things to be seized. Indeed, the warrant expressly and particularly described things such as "controlled substance[s]" and "other paraphernalia used in, for, or in connection with the unlawful possession or use of any controlled substance" that the police had no reason whatsoever to believe were to be found in [468 U.S. 897, 947] respondent's home. App. 17a. Given the Fourth Amendment's requirement that "no Warrants shall issue, but upon probable cause . . . and particularly describing the . . . things to be seized," this warrant should never have been issued. The police who entered respondent's home, therefore, were without constitutional authority to do so.

Although the Court's opinion tends to overlook this fact, the requirement of particularity is not a mere "technicality," it is an express constitutional command. Ybarra v. Illinois, 444 U.S. 85, 92 (1979); Lo-Ji Sales, Inc. v. New York, 442 U.S. 319 (1979); Stanford v. Texas, 379 U.S. 476 (1965); Marron v. United States, 275 U.S. 192, 196 (1927). The purpose of that requirement is to prevent precisely the kind of governmental conduct that the faulty warrant at issue here created a grave risk of permitting - namely, a search that was not narrowly and particularly limited to the things that a neutral and detached magistrate had reason to believe might be found at respondent's home. Although it is true, as JUSTICE STEVENS observes, see post, at 964, that the affidavit submitted by the police set forth with particularity those items that they sought authority to search for, it is nevertheless clear that the warrant itself - the document which actually gave the officers legal authority to invade respondent's privacy - made no mention of these items. And, although it is true that the particular officers who applied for the warrant also happened to execute it and did so in accordance with the limits proposed in their affidavit, this happenstance should have no bearing on the central question whether these officers secured that prior judicial authority to conduct their search required by the Fourth Amendment. As we made clear in United States v. United States District Court, supra, at 317 (footnote omitted), "[t]he Fourth Amendment contemplates a prior judicial judgment, not the risk that executive discretion may be reasonably exercised." See also Katz v. United States, 389 U.S. 347, 356-357 (1967) ("this Court has never sustained a search upon the sole ground that officers reasonably expected to find evidence of a particular crime [468 U.S. 897, 948] and voluntarily confined their activities to the least intrusive means consistent with that end"). Had the warrant actually been enforced by officers other than those who prepared the affidavit, the same result might not have occured; indeed, the wholly erroneous nature of the warrant might have led such officers to feel at liberty to roam throughout respondent's home in search of drugs. Cf. Whiteley v. Warden, 401 U.S. 560 (1971). I therefore fail to see how a search pursuant to such a fundamentally defective warrant can be characterized as "reasonable."

What the Framers of the Bill of Rights sought to accomplish through the express requirements of the Fourth Amendment was to define precisely the conditions under which government agents could search private property so that citizens would not have to depend solely upon the discretion and restraint of those agents for the protection of their privacy. Although the self-restraint and care exhibited by the officers in this case is commendable, that alone can never be a sufficient protection for constitutional liberties. I am convinced that it is not too much to ask that an attentive magistrate take those minimum steps necessary to ensure that every warrant he issues describes with particularity the things that his independent review of the warrant application convinces him are likely to be found in the premises. And I am equally convinced that it is not too much to ask that well-trained and experienced police officers take a moment to check that the warrant they have been issued at least describes those things for which they have sought leave to search. These convictions spring not from my own view of sound criminal law enforcement policy, but are instead compelled by the language of the Fourth Amendment and the history that led to its adoption.

III

Even if I were to accept the Court's general approach to the exclusionary rule, I could not agree with today's result. [468 U.S. 897, 949] There is no question that in the hands of the present Court the deterrence rationale has proved to be a powerful tool for confining the scope of the rule. In Calandra, for example, the Court concluded that the "speculative and undoubtedly minimal advance in the deterrence of police misconduct," was insufficient to outweigh the "expense of substantially impeding the role of the grand jury." 414 U.S. , at 351-352. In Stone v. Powell, the Court found that "the additional contribution, if any, of the consideration of search-and-seizure claims of state prisoners on collateral review is small in relation to the costs." 428 U.S., at 493. In United States v. Janis, 428 U.S. 433 (1976), the Court concluded that "exclusion from federal civil proceedings of evidence unlawfully seized by a state criminal enforcement officer has not been shown to have a sufficient likelihood of deterring the conduct of the state police so that it outweighs the societal costs imposed by the exclusion." Id., at 454. And in an opinion handed down today, the Court finds that the "balance between costs and benefits comes out against applying the exclusionary rule in civil deportation hearings held by the [Immigration and Naturalization Service]." INS v. Lopez-Mendoza, post, at 1050.

Thus, in this bit of judicial stagecraft, while the sets sometimes change, the actors always have the same lines. Given this well-rehearsed pattern, one might have predicted with some assurance how the present case would unfold. First there is the ritual incantation of the "substantial social costs" exacted by the exclusionary rule, followed by the virtually foreordained conclusion that, given the marginal benefits, application of the rule in the circumstances of these cases is not warranted. Upon analysis, however, such a result cannot be justified even on the Court's own terms.

At the outset, the Court suggests that society has been asked to pay a high price - in terms either of setting guilty persons free or of impeding the proper functioning of trials - as a result of excluding relevant physical evidence in cases [468 U.S. 897, 950] where the police, in conducting searches and seizing evidence, have made only an "objectively reasonable" mistake concerning the constitutionality of their actions. See ante, at 907-908. But what evidence is there to support such a claim?

Significantly, the Court points to none, and, indeed, as the Court acknowledges, see ante, at 907-908, n. 6, recent studies have demonstrated that the "costs" of the exclusionary rule - calculated in terms of dropped prosecutions and lost convictions - are quite low. Contrary to the claims of the rule's critics that exclusion leads to "the release of countless guilty criminals," Bivens v. Six Unknown Federal Narcotics Agents, 403 U.S. 388, 416 (1971) (BURGER, C. J., dissenting), these studies have demonstrated that federal and state prosecutors very rarely drop cases because of potential search