Supreme Court of the United States
Booker T. Hudson, Jr. v. Michigan
Decided June 15, 2006 – 547 U.S. 586
Justice SCALIA delivered the opinion of the Court.
We decide whether violation of the “knock-and-announce” rule requires the suppression of all evidence found in the search.
Police obtained a warrant authorizing a search for drugs and firearms at the home of petitioner Booker Hudson. They discovered both. Large quantities of drugs were found, including cocaine rocks in Hudson’s pocket. A loaded gun was lodged between the cushion and armrest of the chair in which he was sitting. Hudson was charged under Michigan law with unlawful drug and firearm possession.
This case is before us only because of the method of entry into the house. When the police arrived to execute the warrant, they announced their presence, but waited only a short time—perhaps “three to five seconds”—before turning the knob of the unlocked front door and entering Hudson’s home. Hudson moved to suppress all the inculpatory evidence, arguing that the premature entry violated his Fourth Amendment rights.
[It was undisputed that the entry was a knock-and-announce violation.]
In Weeks v. United States, we adopted the federal exclusionary rule for evidence that was unlawfully seized from a home without a warrant in violation of the Fourth Amendment. We began applying the same rule to the States, through the Fourteenth Amendment, in Mapp v. Ohio.
Suppression of evidence, however, has always been our last resort, not our first impulse. The exclusionary rule generates “substantial social costs,” which sometimes include setting the guilty free and the dangerous at large. We have therefore been “cautio[us] against expanding” it and “have repeatedly emphasized that the rule’s ‘costly toll’ upon truth-seeking and law enforcement objectives presents a high obstacle for those urging [its] application.” We have rejected “[i]ndiscriminate application” of the rule and have held it to be applicable only “where its remedial objectives are thought most efficaciously served”—that is, “where its deterrence benefits outweigh its ‘substantial social costs.’”
One of those interests is the protection of human life and limb, because an unannounced entry may provoke violence in supposed self-defense by the surprised resident. Another interest is the protection of property. Breaking a house (as the old cases typically put it) absent an announcement would penalize someone who “‘did not know of the process, of which, if he had notice, it is to be presumed that he would obey it ….’” The knock-and-announce rule gives individuals “the opportunity to comply with the law and to avoid the destruction of property occasioned by a forcible entry.” And thirdly, the knock-and-announce rule protects those elements of privacy and dignity that can be destroyed by a sudden entrance. It gives residents the “opportunity to prepare themselves for” the entry of the police. “The brief interlude between announcement and entry with a warrant may be the opportunity that an individual has to pull on clothes or get out of bed.” In other words, it assures the opportunity to collect oneself before answering the door.
What the knock-and-announce rule has never protected, however, is one’s interest in preventing the government from seeing or taking evidence described in a warrant. Since the interests that were violated in this case have nothing to do with the seizure of the evidence, the exclusionary rule is inapplicable.***
Next to these “substantial social costs” we must consider the deterrence benefits, existence of which is a necessary condition for exclusion. (It is not, of course, a sufficient condition: “[I]t does not follow that the Fourth Amendment requires adoption of every proposal that might deter police misconduct.”) To begin with, the value of deterrence depends upon the strength of the incentive to commit the forbidden act. Viewed from this perspective, deterrence of knock-and-announce violations is not worth a lot. Violation of the warrant requirement sometimes produces incriminating evidence that could not otherwise be obtained. But ignoring knock-and-announce can realistically be expected to achieve absolutely nothing except the prevention of destruction of evidence and the avoidance of life-threatening resistance by occupants of the premises—dangers which, if there is even “reasonable suspicion” of their existence, suspend the knock-and-announce requirement anyway. Massive deterrence is hardly required.
In sum, the social costs of applying the exclusionary rule to knock-and-announce violations are considerable; the incentive to such violations is minimal to begin with, and the extant deterrences against them are substantial—incomparably greater than the factors deterring warrantless entries when Mapp was decided. Resort to the massive remedy of suppressing evidence of guilt is unjustified.
For the foregoing reasons we affirm the judgment of the Michigan Court of Appeals.
Justice KENNEDY, concurring in part and concurring in the judgment. [omitted]
In Wilson v. Arkansas (Chapter 7), 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.
As 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 cases the Court has decided in the near century since it first set forth the exclusionary principle in Weeks v. United States.
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.
It is not surprising  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. ***
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. The only costs it mentions are those that typically accompany any use of the Fourth Amendment’s exclusionary principle. 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 “‘cost[ly]’” 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.
* * *
The Court in Hudson v. Michigan reasoned that the police would have found the evidence anyway (even without the Fourth Amendment violation), and Justice Kennedy concurred that there was no evidence of widespread knock-and-announce violations across the land. Although the decision answered only a fairly narrow question—the availability of the exclusionary rule in knock-and-announce cases—its reasoning foreshadowed a further reduction of the scope of the exclusionary rule.
The next cases answer the question of whether ordinary negligence by police—if it results in a violation of constitutional rights—is sufficient to trigger the exclusionary rule, or if instead more culpable misconduct is required.