428 U.S. 465 (1976)

STONE, WARDEN
v.
POWELL.

No. 74-1055.

Supreme Court of United States.

Argued February 24, 1976. Decided July 6, 1976.^[*] CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT.

*467 Robert R. Granucci, Deputy Attorney General of California, argued the cause for petitioner in No. 74-1055. With him on the briefs were Evelle J. Younger, Attorney General, Jack R. Winkler, Chief Assistant Attorney General, Edward P. O'Brien, Assistant Attorney General, and Clifford K. Thompson, Jr., Thomas A. Brady, and Ronald E. Niver, Deputy Attorneys General. Melvin Kent Kammerlohr, Assistant Attorney General of Nebraska, argued the cause for petitioner in No. 74-1222. With him on the brief was Paul L. Douglas, Attorney General.

Robert W. Peterson, by appointment of the Court, 423 U. S. 817, argued the cause and filed a brief for respondent in No. 74-1055. William C. Cunningham argued the cause for respondent in No. 74-1222. With him on the brief was J. Patrick Green.^[†]

John J. Cleary filed a brief for the California Public Defenders Assn. as amicus curiae urging affirmance in No. 74-1055. Briefs of amici curiae urging affirmance in No. 74-1222 were filed by Mary M. Kaufman for the National Alliance Against Racist and Political Repression; by Henry W. McGee, Jr., for the National Conference of Black Lawyers; by Jonathan M. Hyman for the National Lawyers' Guild et al.; and by Theodore A. Gottfried and Robert E. Davison for the National Legal Aid and Defender Assn.

Leon Friedman, Melvin L. Wulf, and Joel M. Gora filed a brief for the American Civil Liberties Union as amicus curiae in both cases. Briefs of amici curiae in No. 74-1222 were filed by Robert L. Shevin, Attorney General, and Stephen R. Koons, Assistant Attorney General, for the State of Florida; by William F. Hyland, Attorney General, David S. Baime, John DeCicco, and Daniel Louis Grossman, Deputy Attorneys General, for the State of New Jersey; by Louis J. Lefkowitz, Attorney General, Samuel A. Hirshowitz, First Assistant Attorney General, and Lillian Z. Cohen, Assistant Attorney General, for the State of New York; and by Frank Carrington, Fred E. Inbau, Wayne W. Schmidt, James R. Thompson, and William K. Lambie for Americans for Effective Law Enforcement, Inc., et al.

*468 MR. JUSTICE POWELL delivered the opinion of the Court.

Respondents in these cases were convicted of criminal offenses in state courts, and their convictions were affirmed on appeal. The prosecution in each case relied upon evidence obtained by searches and seizures alleged by respondents to have been unlawful. Each respondent subsequently sought relief in a Federal District Court by filing a petition for a writ of federal habeas corpus under *469 28 U. S. C. § 2254. The question presented is whether a federal court should consider, in ruling on a petition for habeas corpus relief filed by a state prisoner, a claim that evidence obtained by an unconstitutional search or seizure was introduced at his trial, when he has previously been afforded an opportunity for full and fair litigation of his claim in the state courts. The issue is of considerable importance to the administration of criminal justice.

I

We summarize first the relevant facts and procedural history of these cases.

A

Respondent Lloyd Powell was convicted of murder in June 1968 after trial in a California state court. At about midnight on February 17, 1968, he and three companions entered the Bonanza Liquor Store in San Bernardino, Cal., where Powell became involved in an altercation with Gerald Parsons, the store manager, over the theft of a bottle of wine. In the scuffling that followed Powell shot and killed Parsons' wife. Ten hours later an officer of the Henderson, Nev., Police Department arrested Powell for violation of the Henderson vagrancy ordinance,^[1] and in the search incident to the arrest discovered a .38-caliber revolver with six expended cartridges in the cylinder.

Powell was extradited to California and convicted of *470 second-degree murder in the Superior Court of San Bernardino County. Parsons and Powell's accomplices at the liquor store testified against him. A criminologist testified that the revolver found on Powell was the gun that killed Parsons' wife. The trial court rejected Powell's contention that testimony by the Henderson police officer as to the search and the discovery of the revolver should have been excluded because the vagrancy ordinance was unconstitutional. In October 1969, the conviction was affirmed by a California District Court of Appeal. Although the issue was duly presented, that court found it unnecessary to pass upon the legality of the arrest and search because it concluded that the error, if any, in admitting the testimony of the Henderson officer was harmless beyond a reasonable doubt under Chapman v. California, 386 U. S. 18 (1967). The Supreme Court of California denied Powell's petition for habeas corpus relief.

In August 1971 Powell filed an amended petition for a writ of federal habeas corpus under 28 U. S. C. § 2254 in the United States District Court for the Northern District of California, contending that the testimony concerning the .38-caliber revolver should have been excluded as the fruit of an illegal search. He argued that his arrest had been unlawful because the Henderson vagrancy ordinance was unconstitutionally vague, and that the arresting officer lacked probable cause to believe that he was violating it. The District Court concluded that the arresting officer lacked probable cause and held that even if the vagrancy ordinance was unconstitutional, the deterrent purpose of the exclusionary rule does not require that it be applied to bar admission of the fruits of a search incident to an otherwise valid arrest. In the alternative, that court agreed with the California District Court of Appeal that the admission of the evidence concerning *471 Powell's arrest, if error, was harmless beyond a reasonable doubt.

In December 1974, the Court of Appeals for the Ninth Circuit reversed. 507 F. 2d 93. The court concluded that the vagrancy ordinance was unconstitutionally vague,^[2] that Powell's arrest was therefore illegal, and that although exclusion of the evidence would serve no deterrent purpose with regard to police officers who were enforcing statutes in good faith, exclusion would serve the public interest by deterring legislators from enacting unconstitutional statutes. Id., at 98. After an independent review of the evidence the court concluded that the admission of the evidence was not harmless error since it supported the testimony of Parsons and Powell's accomplices. Id., at 99.

B

Respondent David Rice was convicted of murder in April 1971 after trial in a Nebraska state court. At 2:05 a. m. on August 17, 1970, Omaha police received a telephone call that a woman had been heard screaming at 2867 Ohio Street. As one of the officers sent to that address examined a suitcase lying in the doorway, it exploded, killing him instantly. By August 22 the investigation of the murder centered on Duane Peak, a 15-year-old member of the National Committee to Combat *472 Fascism (NCCF), and that afternoon a warrant was issued for Peak's arrest. The investigation also focused on other known members of the NCCF, including Rice, some of whom were believed to be planning to kill Peak before he could incriminate them. In their search for Peak, the police went to Rice's home at 10:30 that night and found lights and a television on, but there was no response to their repeated knocking. While some officers remained to watch the premises, a warrant was obtained to search for explosives and illegal weapons believed to be in Rice's possession. Peak was not in the house, but upon entering the police discovered, in plain view, dynamite, blasting caps, and other materials useful in the construction of explosive devices. Peak subsequently was arrested, and on August 27, Rice voluntarily surrendered. The clothes Rice was wearing at that time were subjected to chemical analysis, disclosing dynamite particles.

Rice was tried for first-degree murder in the District Court of Douglas County. At trial Peak admitted planting the suitcase and making the telephone call, and implicated Rice in the bombing plot. As corroborative evidence the State introduced items seized during the search, as well as the results of the chemical analysis of Rice's clothing. The court denied Rice's motion to suppress this evidence. On appeal the Supreme Court of Nebraska affirmed the conviction, holding that the search of Rice's home had been pursuant to a valid search warrant. State v. Rice, 188 Neb. 728, 199 N. W. 2d 480 (1972).

In September 1972 Rice filed a petition for a writ of habeas corpus in the United States District Court for Nebraska. Rice's sole contention was that his incarceration was unlawful because the evidence underlying his conviction had been discovered as the result of an illegal *473 search of his home. The District Court concluded that the search warrant was invalid, as the supporting affidavit was defective under Spinelli v. United States, 393 U. S. 410 (1969), and Aguilar v. Texas, 378 U. S. 108 (1964). 388 F. Supp. 185, 190-194 (1974).^[3] The court also rejected the State's contention that even if the warrant was invalid the search was justified because of the valid arrest warrant for Peak and because of the exigent circumstances of the situation—danger to Peak and search for bombs and explosives believed in possession of the NCCF. The court reasoned that the arrest warrant did not justify the entry as the police lacked probable cause to believe Peak was in the house, and further concluded that the circumstances were not sufficiently exigent to justify an immediate warrantless *474 search. Id., at 194-202.^[4] The Court of Appeals for the Eighth Circuit affirmed, substantially for the reasons stated by the District Court. 513 F. 2d 1280 (1975).

Petitioners Stone and Wolff, the wardens of the respective state prisons where Powell and Rice are incarcerated, petitioned for review of these decisions, raising questions concerning the scope of federal habeas corpus and the role of the exclusionary rule upon collateral review of cases involving Fourth Amendment claims. We granted their petitions for certiorari. 422 U. S. 1055 (1975).^[5] We now reverse.

II

The authority of federal courts to issue to writ of habeas corpus ad subjiciendum^[6] was included in the first *475 grant of federal-court jurisdiction, made by the Judiciary Act of 1789, c. 20, § 14, 1 Stat. 81, with the limitation that the writ extend only to prisoners held in custody by the United States. The original statutory authorization did not define the substantive reach of the writ. It merely stated that the courts of the United States "shall have power to issue writs of . . . habeas corpus . . . ." Ibid. The courts defined the scope of the writ in accordance with the common law and limited it to an inquiry as to the jurisdiction of the sentencing tribunal. See, e. g., Ex parte Watkins, 3 Pet. 193 (1830) (Marshall, C. J.).

In 1867 the writ was extended to state prisoners. Act of Feb. 5, 1867, c. 28, § 1, 14 Stat. 385. Under the 1867 Act federal courts were authorized to give relief in "all cases where any person may be restrained of his or her liberty in violation of the constitution, or of any treaty or law of the United States . . . ." But the limitation of federal habeas corpus jurisdiction to consideration of the jurisdiction of the sentencing court persisted. See, e. g., In re Wood, 140 U. S. 278 (1891); In re Rahrer, 140 U. S. 545 (1891); Andrews v. Swartz, 156 U. S. 272 (1895); Bergemann v. Backer, 157 U. S. 655 (1895); Pettibone v. Nichols, 203 U. S. 192 (1906). And, although the concept of "jurisdiction" was subjected to considerable strain as the substantive scope of the writ was expanded,^[7] this *476 expansion was limited to only a few classes of cases^[8] until Frank v. Mangum, 237 U. S. 309, in 1915. In Frank, the prisoner had claimed in the state courts that the proceedings which resulted in his conviction for murder had been dominated by a mob. After the State Supreme Court rejected his contentions, Frank unsuccessfully sought habeas corpus relief in the Federal District Court. This Court affirmed the denial of relief because Frank's federal claims had been considered by a competent and unbiased state tribunal. The Court recognized, however, that if a habeas corpus court found that the State had failed to provide adequate "corrective process" for the full and fair litigation of federal claims, whether or not "jurisdictional," the court could inquire into the merits to determine whether a detention was lawful. Id., at 333-336.

In the landmark decision in Brown v. Allen, 344 U. S. 443, 482-487 (1953), the scope of the writ was expanded still further.^[9] In that case and its companion case, Daniels v. Allen, state prisoners applied for federal habeas corpus relief claiming that the trial courts had erred *477 in failing to quash their indictments due to alleged discrimination in the selection of grand jurors and in ruling certain confessions admissible. In Brown, the highest court of the State had rejected these claims on direct appeal, State v. Brown, 233 N. C. 202, 63 S. E. 2d 99, and this Court had denied certiorari, 341 U. S. 943 (1951). Despite the apparent adequacy of the state corrective process, the Court reviewed the denial of the writ of habeas corpus and held that Brown was entitled to a full reconsideration of these constitutional claims, including, if appropriate, a hearing in the Federal District Court. In Daniels, however, the State Supreme Court on direct review had refused to consider the appeal because the papers were filed out of time. This Court held that since the state-court judgment rested on a reasonable application of the State's legitimate procedural rules, a ground that would have barred direct review of his federal claims by this Court, the District Court lacked authority to grant habeas corpus relief. See 344 U. S., at 458, 486.

This final barrier to broad collateral re-examination of state criminal convictions in federal habeas corpus proceedings was removed in Fay v. Noia, 372 U. S. 391 (1963).^[10] Noia and two codefendants had been convicted *478 of felony murder. The sole evidence against each defendant was a signed confession. Noia's codefendants, but not Noia himself, appealed their convictions. Although their appeals were unsuccessful, in subsequent state proceedings they were able to establish that their confessions had been coerced and their convictions therefore procured in violation of the Constitution. In a subsequent federal habeas corpus proceedings, it was stipulated that Noia's confession also had been coerced, but the District Court followed Daniels in holding that Noia's failure to appeal barred habeas corpus review. See United States v. Fay, 183 F. Supp. 222, 225 (SDNY 1960). The Court of Appeals reversed, ordering that Noia's conviction be set aside and that he be released from custody or that a new trial be granted. This Court affirmed the grant of the writ, narrowly restricting the circumstances in which a federal court may refuse to consider the merits of federal constitutional claims.^[11]

During the period in which the substantive scope of the writ was expanded, the Court did not consider whether exceptions to full review might exist with respect *479 to particular categories of constitutional claims. Prior to the Court's decision in Kaufman v. United States, 394 U. S. 217 (1969), however, a substantial majority of the Federal Courts of Appeals had concluded that collateral review of search-and-seizure claims was inappropriate on motions filed by federal prisoners under 28 U. S. C. § 2255, the modern postconviction procedure available to federal prisoners in lieu of habeas corpus.^[12] The primary rationale advanced in support of those decisions was that Fourth Amendment violations are different in kind from denials of Fifth or Sixth Amendment rights in that claims of illegal search and seizure do not "impugn the integrity of the fact-finding process or challenge evidence as inherently unreliable; rather, the exclusion of illegally seized evidence is simply a prophylactic device intended generally to deter Fourth Amendment violations by law enforcement officers." 394 U. S., at 224. See Thornton v. United States, 125 U. S. App. D. C. 114, 368 F. 2d 822 (1966).

Kaufman rejected this rationale and held that search-and-seizure claims are cognizable in § 2255 proceedings. The Court noted that "the federal habeas remedy extends to state prisoners alleging that unconstitutionally obtained evidence was admitted against them at trial," 394 U. S., at 225, citing, e. g., Mancusi v. DeForte, 392 *480 U. S. 364 (1968); Carafas v. LaVallee, 391 U. S. 234 (1968), and concluded, as a matter of statutory construction, that there was no basis for restricting "access by federal prisoners with illegal search-and-seizure claims to federal collateral remedies, while placing no similar restriction on access by state prisoners," 394 U. S., at 226. Although in recent years the view has been expressed that the Court should re-examine the substantive scope of federal habeas jurisdiction and limit collateral review of search-and-seizure claims "solely to the question of whether the petitioner was provided a fair opportunity to raise and have adjudicated the question in state courts," Schneckloth v. Bustamonte, 412 U. S. 218, 250 (1973) (POWELL, J., concurring),^[13] the Court, without discussion or consideration of the issue, has continued to accept jurisdiction in cases raising such claims. See Lefkowitz v. Newsome, 420 U. S. 283 (1975); Cady v. Dombrowski, 413 U. S. 433 (1973); Cardwell v. Lewis, 417 U. S. 583 (1974) (plurality opinion).^[14]

The discussion in Kaufman of the scope of federal habeas corpus rests on the view that the effectuation of the Fourth Amendment, as applied to the States through the Fourteenth Amendment, requires the granting of habeas corpus relief when a prisoner has been convicted *481 in state court on the basis of evidence obtained in an illegal search or seizure since those Amendments were held in Mapp v. Ohio, 367 U. S. 643 (1961), to require exclusion of such evidence at trial and reversal of conviction upon direct review.^[15] Until these cases we have not had occasion fully to consider the validity of this view. See, e. g., Schneckloth v. Bustamonte, supra, at 249 n. 38; Cardwell v. Lewis, supra, at 596, and n. 12. Upon examination, we conclude, in light of the nature and purpose of the Fourth Amendment exclusionary rule, that this view is unjustified.^[16] We hold, therefore, that *482 where the State has provided an opportunity for full and fair litigation of a Fourth Amendment claim, the Constitution does not require that a state prisoner be granted federal habeas corpus relief on the ground that evidence obtained in an unconstitutional search or seizure was introduced at his trial.^[17]

III

The Fourth Amendment assures the "right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." The Amendment was primarily a reaction to the evils associated with the use of the general warrant in England and the writs of assistance in the Colonies, Stanford v. Texas, 379 U. S. 476, 481-485 (1965); Frank v. Maryland, 359 U. S. 360, 363-365 (1959), and was intended to protect the "sanctity of a man's home and the privacies of life," Boyd v. United States, 116 U. S. 616, 630 (1886), from searches under unchecked general authority.^[18]

The exclusionary rule was a judicially created means of effectuating the rights secured by the Fourth Amendment. Prior to the Court's decisions in Weeks v. United States, 232 U. S. 383 (1914), and Gouled v. United States, 255 U. S. 298 (1921), there existed no barrier to the introduction in criminal trials of evidence obtained in violation of the Amendment. See Adams v. New York, *483 192 U. S. 585 (1904).^[19] In Weeks the Court held that the defendant could petition before trial for the return of property secured through an illegal search or seizure conducted by federal authorities. In Gouled the Court held broadly that such evidence could not be introduced in a federal prosecution. See Warden v. Hayden, 387 U. S. 294, 304-305 (1967). See also Silverthorne Lumber Co. v. United States, 251 U. S. 385 (1920) (fruits of illegally seized evidence). Thirty-five years after Weeks the Court held in Wolf v. Colorado, 338 U. S. 25 (1949), that the right to be free from arbitrary intrusion by the police that is protected by the Fourth Amendment is "implicit in `the concept of ordered liberty' and as such enforceable against the States through the [Fourteenth Amendment] Due Process Clause." Id., at 27-28. The Court concluded, however, that the Weeks exclusionary rule would not be imposed upon the States as "an essential ingredient of [that] right." 338 U. S., at 29. The full force of Wolf was eroded in subsequent decisions, see Elkins v. United States, 364 U. S. 206 (1960); Rea v. United States, 350 U. S. 214 (1956), and a little more than a decade later the exclusionary rule was held applicable to the States in Mapp v. Ohio, 367 U. S. 643 (1961).

*484 Decisions prior to Mapp advanced two principal reasons for application of the rule in federal trials. The Court in Elkins, for example, in the context of its special supervisory role over the lower federal courts, referred to the "imperative of judicial integrity," suggesting that exclusion of illegally seized evidence prevents contamination of the judicial process. 364 U. S., at 222.^[20] But even in that context a more pragmatic ground was emphasized:

"The rule is calculated to prevent, not to repair. Its purpose is to deter—to compel respect for the constitutional guaranty in the only effectively available way—by removing the incentive to disregard it." Id., at 217.

The Mapp majority justified the application of the rule to the States on several grounds,^[21] but relied principally upon the belief that exclusion would deter future unlawful police conduct. 367 U. S., at 658.

*485 Although our decisions often have alluded to the "imperative of judicial integrity," e. g., United States v. Peltier, 422 U. S. 531, 536-539 (1975), they demonstrate the limited role of this justification in the determination whether to apply the rule in a particular context.^[22] Logically extended this justification would require that courts exclude unconstitutionally seized evidence despite lack of objection by the defendant, or even over his assent. Cf. Henry v. Mississippi, 379 U. S. 443 (1965). It also would require abandonment of the standing limitations on who may object to the introduction of unconstitutionally seized evidence. Alderman v. United States, 394 U. S. 165 (1969), and retreat from the proposition that judicial proceedings need not abate when the defendant's person is unconstitutionally seized, Gerstein v. Pugh, 420 U. S. 103, 119 (1975); Frisbie v. Collins, 342 U. S. 519 (1952). Similarly, the interest in promoting judicial integrity does not prevent the use of illegally seized evidence in grand jury proceedings. United States v. Calandra, 414 U. S. 338 (1974). Nor does it require that the trial court exclude such evidence from use for impeachment of a defendant, even though its introduction is certain to result in conviction in some cases. Walder v. United States, 347 U. S. 62 (1954). The teaching of these cases is clear. While courts, of course, must ever be concerned with preserving the integrity of the judicial process, this concern has limited force as a justification for the exclusion of highly probative evidence.^[23]*486 The force of this justification becomes minimal where federal habeas corpus relief is sought by a prisoner who previously has been afforded the opportunity for full and fair consideration of his search-and-seizure claim at trial and on direct review.

The primary justification for the exclusionary rule then is the deterrence of police conduct that violates Fourth Amendment rights. Post-Mapp decisions have established that the rule is not a personal constitutional right. It is not calculated to redress the injury to the privacy of the victim of the search or seizure, for any "[r]eparation comes too late." Linkletter v. Walker, 381 U. S. 618, 637 (1965). Instead,

"the rule is a judicially created remedy designed to safeguard Fourth Amendment rights generally through its deterrent effect . . . ." United States v. Calandra, supra, at 348.

Accord, United States v. Peltier, supra, at 538-539; Terry v. Ohio, 392 U. S. 1, 28-29 (1968); Linkletter v. Walker, supra, at 636-637; Tehan v. United States ex rel. Shott, 382 U. S. 406, 416 (1966).

Mapp involved the enforcement of the exclusionary rule at state trials and on direct review. The decision in Kaufman, as noted above, is premised on the view that implementation of the Fourth Amendment also requires the consideration of search-and-seizure claims upon collateral review of state convictions. But despite the broad deterrent purpose of the exclusionary rule, it has never been interpreted to proscribe the introduction of illegally seized evidence in all proceedings or against all persons. As in the case of any remedial device, "the application of the rule has been restricted to those areas where its remedial *487 objectives are thought most efficaciously served." United States v. Calandra, supra, at 348.^[24] Thus, our refusal to extend the exclusionary rule to grand jury proceedings was based on a balancing of the potential injury to the historic role and function of the grand jury by such extension against the potential contribution to the effectuation of the Fourth Amendment through deterrence of police misconduct:

"Any incremental deterrent effect which might be achieved by extending the rule to grand jury proceedings is uncertain at best. Whatever deterrence of police misconduct may result from the exclusion of illegally seized evidence from criminal trials, it is unrealistic to assume that application of the rule to grand jury proceedings would significantly further that goal. Such an extension would deter only police investigation consciously directed toward the discovery of evidence solely for use in a grand jury investigation. . . . 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 *488 impeding the role of the grand jury." 414 U. S., at 351-352 (footnote omitted).

The same pragmatic analysis of the exclusionary rule's usefulness in a particular context was evident earlier in Walder v. United States, supra, where the Court permitted the Government to use unlawfully seized evidence to impeach the credibility of a defendant who had testified broadly in his own defense. The Court held, in effect, that the interests safeguarded by the exclusionary rule in that context were outweighed by the need to prevent perjury and to assure the integrity of the trial process. The judgment in Walder revealed most clearly that the policies behind the exclusionary rule are not absolute. Rather, they must be evaluated in light of competing policies. In that case, the public interest in determination of truth at trial^[25] was deemed to outweigh the incremental contribution that might have been made to the protection of Fourth Amendment values by application of the rule.

The balancing process at work in these cases also finds expression in the standing requirement. Standing to invoke the exclusionary rule has been found to exist only when the Government attempts to use illegally obtained evidence to incriminate the victim of the illegal 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). See Jones v. United States, 362 U. S. 257, 261 (1960). The standing requirement is premised on the view that the "additional benefits of extending the . . . rule" to defendants other than the victim of the search or seizure are outweighed by the "further encroachment upon the *489 public interest in prosecuting those accused of crime and having them acquitted or convicted on the basis of all the evidence which exposes the truth." Alderman v. United States, supra, at 174-175.^[26]

IV

We turn now to the specific question presented by these cases. Respondents allege violations of Fourth Amendment rights guaranteed them through the Fourteenth Amendment. The question is whether state prisoners— who have been afforded the opportunity for full and fair consideration of their reliance upon the exclusionary rule with respect to seized evidence by the state courts at trial and on direct review—may invoke their claim again on federal habeas corpus review. The answer is to be found by weighing the utility of the exclusionary rule against the costs of extending it to collateral review of Fourth Amendment claims.

The costs of applying the exclusionary rule even at trial and on direct review are well known:^[27] the focus *490 of the trial, and the attention of the participants therein, are diverted from the ultimate question of guilt or innocence that should be the central concern in a criminal proceeding.^[28] Moreover, the physical evidence sought to be excluded is typically reliable and often the most probative information bearing on the guilt or innocence of the defendant. As Mr. Justice Black emphasized in his dissent in Kaufman:

"A claim of illegal search and seizure under the Fourth Amendment is crucially different from many other constitutional rights; ordinarily the evidence seized can in no way have been rendered untrustworthy by the means of its seizure and indeed often this evidence alone establishes beyond virtually any shadow of a doubt that the defendant is guilty." 394 U. S., at 237.

Application of the rule thus deflects the truthfinding process and often frees the guilty. 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.^[29] Thus, *491 although the 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 administration of justice.^[30] These long-recognized costs of the rule persist when a criminal conviction is sought to be overturned on collateral review on the ground that a search-and-seizure claim was erroneously rejected by two or more tiers of state courts.^[31]

*492 Evidence obtained by police officers in violation of the Fourth Amendment is excluded at trial in the hope that the frequency of future violations will decrease. Despite the absence of supportive empirical evidence,^[32] we have assumed that the immediate effect of exclusion will be to discourage law enforcement officials from violating the Fourth Amendment by removing the incentive to disregard it. More importantly, over the long term, this demonstration that our society attaches serious consequences to violation of constitutional rights is thought to encourage those who formulate law enforcement policies, and the officers who impl