Hudson v. Michigan

with whom

In Wilson v. Arkansas, 514 U. S. 927 (1995), a unanimous Court held that the Fourth Amendment normally requires law enforcement officers to knock and announce their presence before entering a dwelling. Today’s opinion holds that evidence seized from a home following a violation of this requirement need not be suppressed.

*605As a result, the Court destroys the strongest legal incentive to comply with the Constitution’s knock-and-announce requirement. And the Court does so without significant support in precedent. At least I can find no such support in the many Fourth Amendment eases the Court has decided in the near century since it first set forth the exclusionary principle in Weeks v. United States, 232 U. S. 383 (1914). See Appendix, infra.

Today’s opinion is thus doubly troubling. It represents a significant departure from the Court’s precedents. And it weakens, perhaps destroys, much of the practical value of the Constitution’s knock-and-announce protection.

I

This Court has set forth the legal principles that ought to have determined the outcome of this case in two sets of basic Fourth Amendment cases. I shall begin by describing that underlying case law.

A

The first set of cases describes the constitutional knock- and-announce requirement, a requirement that this Court initially set forth only 11 years ago in Wilson, supra. Cf. Sabbath v. United States, 391 U. S. 585 (1968) (suppressing evidence seized in violation of federal statutory knock- and-announce requirement); Miller v. United States, 357 U. S. 301 (1958) (same). In Wilson, tracing the lineage of the knock-and-announce rule back to the 13th century, 514 U. S., at 932, and n. 2, we wrote that

“[a]n examination of the common law of search and seizure leaves no doubt that the reasonableness of a search of a dwelling may depend in part on whether law enforcement officers announced their presence and authority prior to entering.” Id., at 931.

We noted that this “basic principle” was agreed upon by “[s]everal prominent founding-era commentators,” id., at 932, *606and “was woven quickly into the fabric of early American law” via state constitutions and statutes, id., at 933. We further concluded that there was

“little doubt that the Framers of the Fourth Amendment thought that the method of an officer’s entry into a dwelling was among the factors to be considered in assessing the reasonableness of a search or seizure.” Id., at 934.

And we held that the “common-law ‘knock and announce’ principle forms a part of the reasonableness inquiry under the Fourth Amendment.” Id., at 929. Thus, “a search or seizure of a dwelling might be constitutionally defective if police officers enter without prior announcement.” Id., at 936; see United States v. Banks, 540 U. S. 31, 36 (2003); United States v. Ramirez, 523 U. S. 65, 70 (1998); Richards v. Wisconsin, 520 U. S. 385, 387 (1997).

B

The second set of cases sets forth certain well-established principles that are relevant here. They include:

Boyd v. United States, 116 U. S. 616 (1886). In this seminal Fourth Amendment case, decided 120 years ago, the Court wrote, in frequently quoted language, that the Fourth Amendment’s prohibitions apply

“to all invasions on the part of the government and its employés of the sanctity of a man’s home and the privacies of life. It is not the breaking of his doors, and the rummaging of his drawers, that constitutes the essence of the offence; but it is the invasion of his indefeasible right of personal security, personal liberty and private property.” Id., at 630.

Weeks, supra. This case, decided 28 years after Boyd, originated the exclusionary rule. The Court held that the Federal Government could not retain evidence seized uncon*607stitutionally and use that evidence in a federal criminal trial. The Court pointed out that “[i]f letters and private documents” could be unlawfully seized from a home “and used in evidence against a citizen accused of an offense, the protection of the Fourth Amendment declaring his right to be secure against such searches and seizures is of no value, and . . . might as well be stricken from the Constitution.” 232 U. S., at 393.

Silverthorne Lumber Co. v. United States, 251 U. S. 385 (1920). This case created an exception to (or a qualification of) Weeks’ exclusionary rule. The Court held that the Government could not use information obtained during an illegal search to subpoena documents that they illegally viewed during that search. Writing for the Court, Justice Holmes noted that the exclusionary rule “does not mean that the facts [unlawfully] obtained become sacred and inaccessible. If knowledge of them is gained from an independent source they may be proved like any others . . . .” 251 U. S., at 392. Silverthorne thus stands for the proposition that the exclusionary rule does not apply if the evidence in question (or the “fruits” of that evidence) was obtained through a process unconnected with, and untainted by, the illegal search. Cf. Nix v. Williams, 467 U. S. 431, 444 (1984) (describing related “inevitable discovery” exception).

Wolf v. Colorado, 338 U. S. 25 (1949), and Mapp v. Ohio, 367 U. S. 643 (1961). Both of these cases considered whether Weeks’ exclusionary rule applies to the States. In Wolf, the Court held that it did not. It said that “[t]he security of one’s privacy against arbitrary intrusion by the police . . . is . .. implicit in ‘the concept of ordered liberty’ and as such enforceable against the States through the Due Process Clause.” 338 U. S., at 27-28. But the Court held that the exclusionary rule is not enforceable against the States as “an essential ingredient of the right.” Id., at 29. In Mapp, the Court overruled Wolf. Experience, it said, showed that alternative methods of enforcing the Fourth Amendment’s re*608quirements had failed. See 367 U. S., at 651-653; see, e. g., People v. Cahan, 44 Cal. 2d 434, 447, 282 P. 2d 905, 913 (1955) (majority opinion of Traynor, J.) (“Experience [in California] has demonstrated, however, that neither administrative, criminal nor civil remedies are effective in suppressing lawless searches and seizures”). The Court consequently held that “all evidence obtained by searches and seizures in violation of the Constitution is, by that same authority, inadmissible in a state court.” Mapp, 367 U. S., at 655. “To hold otherwise,” the Court added, would be “to grant the right but in reality to withhold its privilege and enjoyment.” Id., at 656.

II

Reading our knock-and-announce cases, Part I-A, supra, in light of this foundational Fourth Amendment case law, Part I-B, supra, it is clear that the exclusionary rule should apply. For one thing, elementary logic leads to that conclusion. We have held that a court must “conside[r]” whether officers complied with the knock-and-announce requirement “in assessing the reasonableness of a search or seizure.” Wilson, 514 U. S., at 934; see Banks, supra, at 36. The Fourth Amendment insists that an unreasonable search or seizure is, constitutionally speaking, an illegal search or seizure. And ever since Weeks (in respect to federal prosecutions) and Mapp (in respect to state prosecutions), “the use of evidence secured through an illegal search and seizure” is “barred” in criminal trials. Wolf, supra, at 28 (citing Weeks, 232 U. S. 383); see Mapp, supra, at 655.

For another thing, the driving legal purpose underlying the exclusionary rule, namely, the deterrence of unlawful government behavior, argues strongly for suppression. See Elkins v. United States, 364 U. S. 206, 217 (1960) (purpose of the exclusionary rule is “to deter — to compel respect for the constitutional guaranty ... by removing the incentive to disregard it”). In Weeks, Silverthorne, and Mapp, the Court based its holdings requiring suppression of unlawfully ob*609tained evidence upon the recognition that admission of that evidence would seriously undermine the Fourth Amendment’s promise. All three cases recognized that failure to apply the exclusionary rule would make that promise a hollow one, see Mapp, supra, at 657, reducing it to “a form of words,” Silverthorne, supra, at 392, “of no value” to those whom it seeks to protect, Weeks, supra, at 393. Indeed, this Court in Mapp held that the exclusionary rule applies to the States in large part due to its belief that alternative state mechanisms for enforcing the Fourth Amendment’s guarantees had proved “worthless and futile.” 367 U. S., at 652.

Why is application of the exclusionary rule any the less necessary here? Without such a rule, as in Mapp, police know that they can ignore the Constitution’s requirements without risking suppression of evidence discovered after an unreasonable entry. As in Mapp, some government officers will find it easier, or believe it less risky, to proceed with what they consider a necessary search immediately and without the requisite constitutional (say, warrant or knock-and-announce) compliance. Cf. Mericli, The Apprehension of Peril Exception to the Knock and Announce Rule — Part I, 16 Search and Seizure L. Rep.. 129, 130 (1989) (hereinafter Mericli) (noting that some “[d]rug enforcement authorities believe that safety for the police lies in a swift, surprising entry with overwhelming force — not in announcing their official authority”).

Of course, the State or the Federal Government may provide alternative remedies for knock-and-announce violations. But that circumstance was true of Mapp as well. What reason is there to believe that those remedies (such as private damages actions under Rev. Stat. § 1979, 42 U. S. C. § 1983), which the Court found inadequate in Mapp, can adequately deter unconstitutional police behavior here? See Kamisar, In Defense of the Search and Seizure Exclusionary Rule, 26 Harv. J. L. & Pub. Pol’y 119, 126-129 (2003) (arguing that “five decades of post-Weeks ‘freedom’ from the inhibiting ef*610feet of the federal exclusionary rule failed to produce any meaningful alternative to the exclusionary rule in any jurisdiction” and that there is no evidence that “times have changed” post-Mapp).

The cases reporting knock-and-announce violations are legion. See, e. g., 34 Geo. L. J. Ann. Rev. Crim. Proc. 31-35 (2005) (collecting Courts of Appeals cases); Bremer, 85 A. L. R. 5th 1 (2001) (collecting state-court cases); Brief for Petitioner 16-17 (collecting federal and state cases). Indeed, these cases of reported violations seem sufficiently frequent and serious as to indicate “a widespread pattern.” Ante, at 604 (Kennedy, J., concurring in part and concurring in judgment). Yet the majority, like Michigan and the United States, has failed to cite a single reported case in which a plaintiff has collected more than nominal damages solely as a result of a knock-and-announce violation. Even Michigan concedes that, “in cases like the present one . . . , damages may be virtually nonexistent.” Brief for Respondent 35, n. 66. And Michigan’s amici further concede that civil immunities prevent tort law from being an effective substitute for the exclusionary rule at this time. Brief for Criminal Justice Legal Foundation 10; see also Hope v. Pelzer, 536 U. S. 730, 739 (2002) (difficulties of overcoming qualified immunity defenses).

As Justice Stewart, the author of a number of significant Fourth Amendment opinions, explained, the deterrent effect of damages actions “can hardly be said to be great,” as such actions are “expensive, time-consuming, not readily available, and rarely successful.” The Road to Mapp v. Ohio and Beyond: The Origins, Development and Future of the Exclusionary Rule in Search-and-Seizure Cases, 83 Colum. L. Rev. 1365, 1388 (1983). The upshot is that the need for deterrence — the critical factor driving this Court’s Fourth Amendment cases for close to a century — argues with at least comparable strength for evidentiary exclusion here.

*611To argue, as the majority does, that new remedies, such as 42 U. S. C. § 1983 actions or better trained police, make suppression unnecessary is to argue that Wolf, not Mapp, is now the law. (The Court recently rejected a similar argument in Dickerson v. United States, 530 U. S. 428, 441-442 (2000).) To argue that there may be few civil suits because violations may produce nothing “more than nominal injury” is to confirm, not to deny, the inability of civil suits to deter violations. See ante, at 598. And to argue without evidence (and despite myriad reported cases of violations, no reported case of civil damages, and Michigan’s concession of their nonexistence) that civil suits may provide deterrence because claims may “have been settled” is, perhaps, to search in desperation for an argument. See ibid. Rather, the majority, as it candidly admits, has simply “assumed” that, “[a]s far as [it] know[s], civil liability is an effective deterrent,” ibid., a support-free assumption that Mapp and subsequent cases make clear does not embody the Court’s normal approach to difficult questions of Fourth Amendment law.

It is not surprising, then, that after looking at virtually every pertinent Supreme Court case decided since Weeks, I can find no precedent that might offer the majority support for its contrary conclusion. The Court has, of course, recognized that not every Fourth Amendment violation necessarily triggers the exclusionary rule. Ante, at 590-592; cf. Illinois v. Gates, 462 U. S. 213, 223 (1983) (application of the exclusionary rule is a separate question from whether the Fourth Amendment has been violated). But the class of Fourth Amendment violations that do not result in suppression of the evidence seized, however, is limited.

The Court has declined to apply the exclusionary rule only:

(1) where there is a specific reason to believe that application of the rule would “not result in appreciable deterrence,” United States v. Janis, 428 U. S. 433, 454 (1976); see, e. g., United States v. Leon, 468 U. S. 897, 919-920 *612(1984) (exception where searching officer executes defective search warrant in “good faith”); Arizona v. Evans, 514 U. S. 1, 14 (1995) (exception for clerical errors by court employees); Walder v. United States, 347 U. S. 62 (1954) (exception for impeachment purposes), or (2) where admissibility in proceedings other than criminal trials was at issue, see, e. g., Pennsylvania Bd. of Probation and Parole v. Scott, 524 U. S. 357, 364 (1998) (exception for parole revocation proceedings); INS v. Lopez-Mendoza, 468 U. S. 1032, 1050 (1984) (plurality opinion) (exception for deportation proceedings); Janis, supra, at 458 (exception for civil tax proceedings); United States v. Calandra, 414 U. S. 338, 348-350 (1974) (exception for grand jury proceedings); Stone v. Powell, 428 U. S. 465, 493-494 (1976) (exception for federal habeas proceedings).

Neither of these two exceptions applies here. The second does not apply because this case is an ordinary criminal trial. The first does not apply because (1) officers who violate the rule are not acting “as a reasonable officer would and should act in similar circumstances,” Leon, supra, at 920, (2) this case does not involve government employees other than police, Evans, supra, and (3), most importantly, the key rationale for any exception, “lack of deterrence,” is missing, see Pennsylvania Bd. of Probation, supra, at 364 (noting that the rationale for not applying the rule in noncriminal cases has been that the deterrence achieved by having the rule apply in those contexts is “minimal” because “application of the rule in the criminal trial context already provides significant deterrence of unconstitutional searches”); Michigan v. Tucker, 417 U. S. 433, 447 (1974) (noting that deterrence rationale would not be served if rule applied to police officers acting in good faith, as the “deterrent purpose of the exclusionary rule necessarily assumes that the police have engaged in willful, or at the very least negligent, conduct”). That critical latter rationale, which underlies every excep*613tion, does not apply here, as there is no reason to think that, in the case of knock-and-announce violations by the police, “the exclusion of evidence at trial would not sufficiently deter future errors,” Evans, supra, at 14, or “‘further the ends of the exclusionary rule in any appreciable way,’ ” Leon, supra, at 919-920.

I am aware of no other basis for an exception. The Court has decided more than 300 Fourth Amendment cases since Weeks. The Court has found constitutional violations in nearly a third of them. See W. Greenhalgh, The Fourth Amendment Handbook: A Chronological Survey of Supreme Court Decisions 27-130 (2d ed. 2003) (collecting and summarizing 332 post-Weeks cases decided between 1914 and 2002). The nature of the constitutional violation varies. In most instances officers lacked a warrant; in others, officers possessed a warrant based on false affidavits; in still others, the officers executed the search in an unconstitutional manner. But in every case involving evidence seized during an illegal search of a home (federally since Weeks, nationally since Mapp), the Court, with the exceptions mentioned, has either explicitly or implicitly upheld (or required) the suppression of the evidence at trial. See Appendix, infra. In not one of those cases did the Court “questio[n], in the absence of a more efficacious sanction, the continued application of the [exclusionary] rule to suppress evidence from the State’s case” in a criminal trial. Franks v. Delaware, 438 U. S. 154, 171 (1978).

I can find nothing persuasive in the majority’s opinion that could justify its refusal to apply the rule. It certainly is not a justification for an exception here (as .the majority finds) to find odd instances in other areas of law that do not automatically demand suppression. Ante, at 596-597 (suspect confesses, police beat him up afterwards; suspect confesses, then police apparently arrest him, take him to station, and refuse to tell him of his right to counsel). Nor can it justify an exception to say that some police may knock at the door *614anyway (to avoid being mistaken for a burglar), for other police (believing quick entry is the most secure, effectivé entry) will not voluntarily do so. Cf. Mericli 130 (describing Special Weapons and Tactics (SWAT) team practices); R. Balko, No SWAT (Apr. 6, 2006), available at http://www. cato.org/pub_display.php?pub_id=6344 (all Internet materials as visited June 7, 2006, and available in Clerk of Court’s case file).

Neither can the majority justify its failure to respect the need for deterrence, as set forth consistently in the Court’s prior case law, through its claim of “‘substantial, social costs’” — at least if it means that those “‘social costs’” are somehow special here. Ante, at 596. The only costs it mentions are those that typically accompany any use of the Fourth Amendment’s exclusionary principle: (1) that where’ the constable blunders, a guilty defendant may be set free (consider Mapp itself); (2) that defendants may assert claims where Fourth Amendment rights are uncertain (consider the Court’s qualified immunity jurisprudence), and (3) that sometimes it is difficult to decide the merits of those uncertain claims. See ante, at 595-596. In fact, the “no-knock” warrants that are provided by many States, by diminishing uncertainty, may make application of the knock-and-announce principle less “‘eost[lyj’” on the whole than application of comparable Fourth Amendment principles, such as determining whether a particular warrantless search was justified by exigency. The majority’s “substantial social costs” argument is an argument against the Fourth Amendment’s exclusionary principle itself. And it is an argument that this Court, until now, has consistently rejected.

Ill

The majority, Michigan, and the United States make several additional arguments. In my view, those arguments rest upon misunderstandings of the principles underlying this Court’s precedents.

*615A

The majority first argues that “the constitutional violation of an illegal manner of entry was not a but-for cause of obtaining the evidence.” Ante, at 592. But taking causation as it is commonly understood in the law, I do not see how that can be so. See W. Keeton, D. Dobbs, R. Keeton, & D. Owen, Prosser and Keeton on Law of Torts 266 (5th ed. 1984). Although the police might have entered Hudson’s home lawfully, they did not in fact do so. Their unlawful behavior inseparably characterizes their actual entry; that entry was a necessary condition of their presence in Hudson’s home; and their presence in Hudson’s home was a necessary condition of their finding and seizing the evidence. At the same time, their discovery of evidence in Hudson’s home was a readily foreseeable consequence of their entry and their unlawful presence within the home. Cf. 2 Restatement (Second) of Torts §435 (1963-1964).

Moreover, separating the “manner of entry” from the related search slices the violation too finely. As noted, Part I-A, swpra, we have described a failure to comply with the knock-and-announce rule, not as an independently unlawful event, but as a factor that renders the search “constitutionally defective.” Wilson, 514 U. S., at 936; see also id., at 934 (compliance with the knock-and-announce requirement is one- of the “factors to be considered in assessing the reasonableness of a search or seizure” (emphasis added)); Ker v. California, 374 U. S. 23, 53 (1963) (opinion of Brennan, J.) (“[A] lawful entry is the indispensable predicate of a reasonable search”).

The Court nonetheless accepts Michigan’s argument that the requisite but-for causation is not satisfied in this case because, whether or not the constitutional violation occurred (what the Court refers to as a “preliminary misstep”), “the police would have executed the warrant they had obtained, and would have discovered the gun and drugs inside the *616house.” Ante, at 592. As support for this proposition, Michigan rests on this Court’s inevitable discovery cases.

This claim, however, misunderstands the inevitable discovery doctrine. Justice Holmes in Silverthorne, in discussing an “independent source” exception, set forth the principles underlying the inevitable discovery rule. See supra, at 607. That rule does not refer to discovery that would have taken place if the police behavior in question had (contrary to fact) been lawful. The doctrine does not treat as critical what hypothetically could have happened had the police acted lawfully in the first place. Rather, “independent” or “inevitable” discovery refers to discovery that did occur or that would have occurred (1) despite (not simply in the absence of) the unlawful behavior and (2) independently of that unlawful behavior. The government cannot, for example, avoid suppression of evidence seized without a warrant (or pursuant to a defective warrant) simply by showing that it could have obtained a valid warrant had it sought one. See, e. g., Coolidge v. New Hampshire, 403 U. S. 443, 450-451 (1971). Instead, it must show that the same evidence “inevitably would have been discovered by lawful means.” Nix v. Williams, 467 U. S., at 444 (emphasis added). “What a man could do is not at all the same as what he would do.” Austin, Ifs And Cans, 42 Proceedings of the British Academy 109, 111-112 (1956).

The inevitable discovery exception rests upon the principle that the remedial purposes of the exclusionary rule are not served by suppressing evidence discovered through a “later, lawful seizure” that is “genuinely independent of an earlier, tainted one.” Murray v. United States, 487 U. S. 533, 542 (1988) (emphasis added); see also id., at 545 (Marshall, J., joined by Stevens and O’Connor, JJ., dissenting) (“When the seizure of the evidence at issue is ‘wholly independent of’ the constitutional violation, then exclusion arguably will have no effect on a law enforcement officer’s incentive to commit an unlawful search”).

*617Case law well illustrates the meaning of this principle. In Nix, supra, police officers violated a defendant’s Sixth Amendment right by eliciting incriminating statements from him after he invoked his right to counsel. Those statements led to the discovery of the victim’s body. The Court concluded that evidence obtained from the victim’s body was admissible because it would ultimately or inevitably have been discovered by a volunteer search party effort that was ongoing — whether or not the Sixth Amendment violation had taken place. Id., at 449. In other words, the evidence would have been found despite, and independent of, the Sixth Amendment violation.

In Segura v. United States, 468 U. S. 796 (1984), one of the “trio of cases” Justice Scalia says “confirms [the Court’s] conclusion,” ante, at 599-600 (plurality opinion), the Court held that an earlier illegal entry into an apartment did not require suppression of evidence that police later seized when executing a search warrant obtained on the basis of information unconnected to the initial entry. The Court reasoned that the “evidence was discovered the day following the entry, during the search conducted under a valid warrant” — i. e., a warrant obtained independently without use of any information found during the illegal entry — and that “it was the product of that search, wholly unrelated to the prior [unlawful] entry.” Segura, supra, at 814 (emphasis added).

In Murray, supra, the Court upheld the admissibility of seized evidence where agents entered a warehouse without a warrant, and then later returned with a valid warrant that was not obtained on the basis of evidence observed during the first (illegal) entry. The Court reasoned that while the agents’ “[knowledge that the marijuana was in the warehouse was assuredly acquired at the time of the unlawful entry ... it was also acquired at the time of entry pursuant to the warrant, and if that later acquisition was not the result of the earlier entry there is no reason why the independ*618ent source doctrine should not apply.” Id., at 541 (emphasis added).

Thus, the Court’s opinion reflects a misunderstanding of what “inevitable discovery” means when it says, “[i]n this case, of course, the constitutional violation of an illegal manner of entry was not a but-for cause of obtaining the evidence.” Ante, at 592. The majority rests this conclusion on its next statement: “Whether that preliminary misstep had occurred or not, the police . . . would have discovered the gun and drugs inside the house.” Ibid. Despite the phrase “of course,” neither of these statements is correct. It is not true that, had the illegal entry not occurred, “police . . . would have discovered the gun and drugs inside the house.” Without that unlawful entry they would not have been inside the house; so there would have been no discovery. See supra, at 615.

Of course, had the police entered the house lawfully, they would have found the gun and drugs. But that fact is beside the point. The question is not what police might have done had they not behaved unlawfully. The question is what they did do. Was there set in motion an independent chain of events that would have inevitably led to the discovery and seizure of the evidence despite, and independent of, that behavior? The answer here is “no.”

B

The majority, Michigan, and the United States point out that the officers here possessed a warrant authorizing a search. Ante, at 592. That fact, they argue, means that the evidence would have been discovered independently or somehow diminishes the need to suppress the evidence. But I do not see why that is so. The warrant in question was not a “no-knock” warrant, which many States (but not Michigan) issue to assure police that a prior knock is not necessary. Richards, 520 U. S., at 396, n. 7 (collecting state statutes). It did not authorize a search that fails to comply with knock- *619and-announce requirements. Rather, it was an ordinary-search warrant. It authorized a search that complied with, not a search that disregarded, the Constitution’s knock-and-announce rule.

Would a warrant that authorizes entry into a home on Tuesday permit the police to enter on Monday? Would a warrant that authorizes entry during the day authorize the police to enter during the middle of the night? It is difficult for me to see how the presence of a warrant that does not authorize the entry in question has anything to do with the “inevitable discovery” exception or otherwise diminishes the need to enforce the knock-and-announce requirement through suppression.

C

The majority and the United States set forth a policy-related variant of the causal connection theme: The United States argues that the law should suppress evidence only insofar as a Fourth Amendment violation causes the kind of harm that the particular Fourth Amendment rule seeks to protect against. It adds that the constitutional purpose of the knock-and-announce rule is to prevent needless destruction of property (such as breaking down a door) and to avoid unpleasant surprise. And it concludes that the exclusionary rule should suppress evidence of, say, damage to property, the discovery of a defendant in an “intimate or compromising moment,” or an excited utterance from the occupant caught by surprise, but nothing more. Brief for United States as Amicus Curiae 12, 28.

The majority makes a similar argument. It says that evidence should not be suppressed once the causal connection between unlawful behavior and discovery of the evidence becomes too “attenuated.” Ante, at 592. But the majority then makes clear that it is not using the word “attenuated” to mean what this Court’s precedents have typically used that word to mean, namely, that the discovery of the evidence has come about long after the unlawful behavior took *620place or in an independent way, i. e., through “ ‘means sufficiently distinguishable to be purged of the primary taint.’ ” Wong Sun v. United States, 371 U. S. 471, 487-488 (1963); see Brown v. Illinois, 422 U. S. 590, 603-604 (1975).

Rather, the majority gives the word “attenuation” a new meaning (thereby, in effect, making the same argument as the United States). “Attenuation,” it says, “also occurs when, even given a direct causal connection, the interest protected by the constitutional guarantee that has been violated would not be served by suppression of the evidence obtained.” Ante, at 593. The interests the knock-and-announce rule seeks to protect, the Court adds, are “human life” (at stake when a householder is “surprised”