opinion: Mr. Justice Brennan
  delivered the opinion of the Court.
  We review in this case the validity of the proposition that there is under the Fourth Amendment a “distinction between merely evidentiary materials, on the one hand, which may not be seized either under the authority of a search warrant or during the course of a search incident to arrest, and on the other hand, those objects which may validly be seized including the instrumentalities and means by which a crime is committed, the fruits of crime such as stolen property, weapons by which escape of the person arrested might be effected, and property the possession of which is a crime.”
  A Maryland court sitting without a jury convicted respondent of armed robbery. Items of his clothing, a cap, jacket,- and trousers, among other things, were seized during a search of his home, and were admitted in evidence without objection. After unsuccessful state court proceedings, he sought and was denied federal habeas corpus relief in the District Court for Maryland. A divided panel of the Court of Appeals for the Fourth Circuit reversed. 363 F. 2d 647. The Court of Appeals believed that Harris v. United States, 331 U. S. 145, 154, sustained the validity of the search, but held that respondent was correct in his contention that the clothing seized was improperly admitted in evidence because the items had “evidential value only” and therefore were not lawfully subject to seizure. We granted certiorari. 385 U. S. 926. We reverse.
  I.
  About 8 a. m. on March 17, 1962, an armed robber entered the business premises of the Diamond Cab Company in Baltimore, Maryland. He took some $363 and ran. Two cab drivers in the vicinity, attracted by shouts of “Holdup,” followed the man to 2111 Cocoa Lane. One driver notified the company dispatcher by radio that the man was a Negro about 5'8" tall, wearing a light cap and dark jacket, and that he had entered the house on Cocoa Lane. The dispatcher relayed the information to police who were proceeding to the scene of the robbery. Within minutes, police arrived at the house in a number of patrol cars. An officer knocked and announced their presence. Mrs. Hayden answered, and the officers told her they believed that a robber had entered the house, and asked to search the house. She offered no objection.
  The officers spread out through the first and second floors and the cellar in search of the robber. Hayden was found in an upstairs bedroom feigning sleep. He was arrested when the officers on the first floor and in the cellar reported that no other man was in the house. Meanwhile an officer was attracted to an adjoining bathroom by the noise of running water, and discovered a shotgun and a pistol in a flush tank; another officer who, according to the District Court, “was searching the cellar for a man or the money” found in a washing machine a jacket and trousers of the type the fleeing man was said to have worn. A clip of ammunition for the pistol and a cap were found under the mattress of Hayden’s bed, and ammunition for the shotgun was found in a bureau drawer in Hayden’s room. All these items of evidence were introduced against respondent at his trial.
  II.
  We agree with the Court of Appeals that neither the entry without warrant to search for the robber, nor the search for him without warrant was invalid. Under the circumstances of this case, “the exigencies of the situation made that course imperative.” McDonald v. United States, 335 U. S. 451, 456. The police were informed that an armed robbery had taken place, and that the suspect had entered 2111 Cocoa Lane less than five minutes before they reached it. They acted reasonably when they entered the house and began to search for a man of the description they had been given and for weapons which he had used in the robbery or might use against them. The Fourth Amendment does not require police officers to delay in the course of an investigation if to do so would gravely endanger their lives or the lives of others. Speed here was essential, and only a thorough search of the house for persons and weapons could have insured that Hayden was the only man present and that the police had control of all weapons which could be used against them or to effect an escape.
  We do not rely upon Harris v. United States, supra, in sustaining the validity of the search. The principal issue in Harris was whether the search there could properly be regarded as incident to the lawful arrest, since Harris was in custody before the search was made and the evidence seized. Here, the seizures occurred prior to or immediately contemporaneous with Hayden’s arrest, as part of an effort to find a suspected felon, armed, within the house into which he had run only minutes before the police arrived. The permissible scope of search must, therefore, at the least, be as broad as may reasonably be necessary to prevent the dangers that the suspect at large in the house may resist or escape.
  It is argued that, while the weapons, ammunition, and cap may have been seized in the course of a search for weapons, the officer who seized the clothing was searching neither for the suspect nor for weapons when he looked into the washing machine in which he found the clothing. But even if we assume, although we do not decide, that the exigent circumstances in this case made lawful a search without warrant only for the suspect or his weapons, it cannot be said on this record that the officer who found the clothes in the washing machine was not searching for weapons. He testified that he was searching for the man or the money, but his failure to state explicitly that he was searching for weapons, in the absence of a specific question to that effect, can hardly be accorded controlling weight. He knew that the robber was armed and he did not know that some weapons had been found at the time he opened the machine. In these circumstances the inference that he was in fact also looking for weapons is fully justified.
  III.
  We come, then, to the question whether, even though the search was lawful, the Court of Appeals was correct in holding that the seizure and introduction of the items of clothing violated the Fourth Amendment because they are “mere evidence.” The distinction made by some of our cases between seizure of items of evidential value only and seizure of instrumentalities, fruits, or contraband has been criticized by courts and commentators. The Court of Appeals, however, felt “obligated to adhere to it.” 363 F. 2d, at 655. We today reject the distinction as based on premises no longer accepted as rules governing the application of the Fourth Amendment.
  We have examined on many occasions the history and purposes of the Amendment. It was a reaction to the evils of the use of the general warrant in England and the writs of assistance in the Colonies, and was intended to protect against invasions of “the sanctity of a man’s home and the privacies of life,” Boyd v. United States, 116 U. S. 616, 630, from searches under indiscriminate, general authority. Protection of these interests was assured by prohibiting all “unreasonable” searches and seizures, and by requiring the use of warrants, which particularly describe “the place to be searched, and the persons or things to be seized,” thereby interposing “a magistrate between the citizen and the police,” McDonald v. United States, supra, 335 U. S., at 455.
  Nothing in the language of the Fourth Amendment supports the distinction between “mere evidence” and instrumentalities, fruits of crime, or contraband. On its face, the provision assures the “right of the people to be secure in their persons, houses, papers, and effects . . . ,” without regard to the use to which any of these things are applied. This “right of the people” is certainly unrelated to the “mere evidence” limitation. Privacy is disturbed no more by a search directed to a purely evidentiary object than it is by a search directed to an instrumentality, fruit, or contraband. A magistrate can intervene in both situations, and the requirements of probable cause and specificity can be preserved intact. Moreover, nothing in the nature of property seized as evidence renders it more private than property seized, for example, as an instrumentality; quite the opposite may be true. Indeed, the distinction is wholly irrational, since, depending on the circumstances, the same “papers and effects” may be “mere evidence” in one case and “instrumentality” in another. See Comment, 20 U. Chi. L. Rev. 319, 320-322 (1953).
  In Gouled v. United States, 255 U. S. 298, 309, the Court said that search warrants “may not be used as a means of gaining access to a man’s house or office and papers solely for the purpose of making search to secure evidence to be used against him in a criminal or penal proceeding . . . .” The Court derived from Boyd v. United States, supra, the proposition that warrants “may be resorted to only when a primary right to such search and seizure may be found in the interest which the public or the complainant may have in the property to be seized, or in the right to the possession of it, or when a valid exercise of the police power renders possession of the property by the accused unlawful and provides that it may be taken,” 255 U. S., at 309; that is, when the property is an instrumentality or fruit of crime, or contraband. Since it was “impossible to say, on the record . . . that the Government had any interest” in the papers involved “other than as evidence against the accused . . . ,” “to permit them to be used in evidence would be, in effect, as ruled in the Boyd Case, to compel the defendant to become a witness against himself.” Id., at 311.
  The items of clothing involved in this case are not “testimonial” or “communicative” in nature, and their introduction therefore did not compel respondent to become a witness against himself in violation of the Fifth Amendment. Schmerber v. California, 384 U. S. 757. This case thus does not require that we consider whether there are items of evidential value whose very nature precludes them from being the object of a reasonable search and seizure.
  The Fourth Amendment ruling in Gouled was based upon the dual, related premises that historically the right to search for and seize property depended upon the assertion by the Government of a valid claim of superior interest, and that it was not enough that the purpose of the search and seizure was to obtain evidence to use in apprehending and convicting criminals. The common law of search and seizure after Entick v. Carrington, 19 How. St. Tr. 1029, reflected Lord Camden’s view, derived no doubt from the political thought of his time, that the “great end, for which men entered into society, was to secure their property.” Id., at 1066. Warrants were “allowed only where the primary right to such a search and seizure is in the interest which the public or complainant may have in the property seized.” Lasson, The History and Development of the Fourth Amendment to the United States Constitution 133-134. Thus stolen property — the fruits of crime — was always subject to seizure. And the power to search for stolen property was gradually extended to cover “any property which the private citizen was not permitted to possess,” which included instrumentalities of crime (because of the early notion that items used in crime were forfeited to the State) and contraband. Kaplan, Search and Seizure: A No-Man’s Land in the Criminal Law, 49 Calif. L. Rev. 474, 475. No separate governmental interest in seizing evidence to apprehend and convict criminals was recognized; it was required that some property interest be asserted. The remedial structure also reflected these dual premises. Trespass, replevin, and the other means of redress for persons aggrieved by searches and seizures, depended upon proof of a superior property interest. And since a lawful seizure presupposed a superior claim, it was inconceivable that a person could recover property lawfully seized. As Lord Camden pointed out in Entick v. Carrington, supra, at 1066, a general warrant enabled “the party’s own property [to be] seized before and without conviction, and he has no power to reclaim his goods, even after his innocence is cleared by acquittal.”
  The premise that property interests control the right of the Government to search and seize has been discredited. Searches and seizures may be “unreasonable” within the Fourth Amendment even though the Government asserts a superior property interest at common law. We have recognized that the principal object of the Fourth Amendment is the protection of privacy rather than property, and have increasingly discarded fictional and procedural barriers rested on property concepts. See Jones v. United States, 362 U. S. 257, 266; Silverman v. United States, 365 U. S. 505, 511. This shift in emphasis from property to privacy has come about through a subtle interplay of substantive and procedural reform. The remedial structure at the time even of Weeks v. United States, 232 U. S. 383, was arguably explainable in property terms. The Court held in Weeks that a defendant could petition before trial for the return of his illegally seized property, a proposition not necessarily inconsistent with Adams v. New York, 192 U. S. 585, which held in effect that the property issues involved in search and seizure are collateral to a criminal proceeding. The remedial structure finally escaped the bounds of common law property limitations in Silverthorne Lumber Co. v. United States, 251 U. S. 385, and Gouled v. United States, supra, when it became established that suppression might be sought during a criminal trial, and under circumstances which would not sustain an action in trespass or replevin. Recognition that the role of the Fourth Amendment was to protect against invasions of privacy demanded a remedy to condemn the seizure in Silverthorne, although no possible common law claim existed for the return of the copies made by the Government of the papers it had seized. The remedy of suppression, necessarily involving only the limited, functional consequence of excluding the evidence from trial, satisfied that demand.
  The development of search and seizure law since Silver-thorne and Gouled is replete with examples of the transformation in substantive law brought about through the interaction of the felt need to protect privacy from unreasonable invasions and the flexibility in rulemaking made possible by the remedy of exclusion. We have held, for example, that intangible as well as tangible evidence may be suppressed, Wong Sun v. United States, 371 U. S. 471, 485-486, and that an actual trespass under local property law is unnecessary to support a remediable violation of the Fourth Amendment, Silverman v. United States, supra. In determining whether someone is a “person aggrieved by an unlawful search and seizure” we have refused “to import into the law . . . subtle distinctions, developed and refined by the common law in evolving the body of private property law which, more than almost any other branch of law, has been shaped by distinctions whose validity is largely historical.” Jones v. United States, supra, 362 U. S., at 266. And with particular relevance here, we have given recognition to the interest in privacy despite the complete absence of a property claim by suppressing the very items which at common law could be seized with impunity: stolen goods, Henry v. United States, 361 U. S. 98; instrumentalities, Beck v. Ohio, 379 U. S. 89; McDonald v. United States, supra; and contraband, Trupiano v. United States, 334 U. S. 699; Aguilar v. Texas, 378 U. S. 108.
  The premise in Gouled that government may not seize evidence simply for the purpose of proving crime has likewise been discredited. The requirement that the Government assert in addition some property interest in material it seizes has long been a fiction, obscuring the reality that government has an interest in solving crime. Schmerber settled the proposition that it is reasonable, within the terms of the Fourth Amendment, to conduct otherwise permissible searches for the purpose of obtaining evidence which would aid in apprehending and convicting criminals. The requirements of the Fourth Amendment can secure the same protection of privacy whether the search is for “mere evidence” or for fruits, instrumentalities or contraband. There must, of course, be a nexus — automatically provided in the case of fruits, instrumentalities or contraband — between the item to be seized and criminal behavior. Thus in the case of “mere evidence,” probable cause must be examined in terms of cause to believe that the evidence sought will aid in a particular apprehension or conviction. In so doing, consideration of police purposes will be required. Cf. Kremen v. United States, 353 U. S. 346. But no such problem is presented in this case. The clothes found in the washing machine matched the description of those worn by the robber and the police therefore could reasonably believe that the items would aid in the identification of the culprit.
  The remedy of suppression, moreover, which made possible protection of privacy from unreasonable searches without regard to proof of a superior property interest, likewise provides the procedural device necessary for allowing otherwise permissible searches and seizures conducted solely to obtain evidence of crime. For just as the suppression of evidence does not entail a declaration of superior property interest in the person aggrieved, thereby enabling him to suppress evidence unlawfully seized despite his inability to demonstrate such an interest (as with fruits, instrumentalities, contraband), the refusal to suppress evidence carries no declaration of superior property interest in the State, and should thereby enable the State to introduce evidence lawfully seized despite its inability to demonstrate such an interest. And, unlike the situation at common law, the owner of property would not be rendered remediless if “mere evidence” could lawfully be seized to prove crime. For just as the suppression of evidence does not in itself necessarily entitle the aggrieved person to its return (as, for example, contraband), the introduction of “mere evidence” does not in itself entitle the State to its retention. Where public officials “unlawfully seize or hold a citizen’s realty or chattels, recoverable by appropriate action at law or in equity . . . ,” the true owner may “bring his possessory action to reclaim that which is wrongfully withheld.” Land v. Dollar, 330 U. S. 731, 738. (Emphasis added.) See Burdeau v. McDowell, 256 U. S. 465, 474.
  The survival of the Gouled distinction is attributable more to chance than considered judgment. Legislation has helped perpetuate it. Thus, Congress has never authorized the issuance of search warrants for the seizure of mere evidence of crime. See Davis v. United States, 328 U. S. 582, 606 (dissenting opinion of Mr. Justice Frankfurter). Even in the Espionage Act of 1917, where Congress for the first time granted general authority for the issuance of search warrants, the authority was limited to fruits of crime, instrumentalities, and certain contraband. 40 Stat. 228. Gouled concluded, needlessly it appears, that the Constitution virtually limited searches and seizures to these categories. After Gouled, pressure to test this conclusion was slow to mount. Rule 41 (b) of the Federal Rules of Criminal Procedure incorporated the Gouled categories as limitations on federal authorities to issue warrants, and Mapp v. Ohio, 367 U. S. 643, only recently made the “mere evidence” rule a problem in the state courts. Pressure against the rule in the federal courts has taken the form rather of broadening the categories of evidence subject to seizure, thereby creating considerable confusion in the law. See, e. g., Note, 54 Geo. L. J. 593, 607-621 (1966).
  The rationale most frequently suggested for the rule preventing the seizure of evidence is that “limitations upon the fruit to be gathered tend to limit the quest itself.” United States v. Poller, 43 F. 2d 911, 914 (C. A. 2d Cir. 1930). But privacy “would be just as well served by a restriction on search to the even-numbered days of the month. . . . And it would have the extra advantage of avoiding hair-splitting questions . . . .” Kaplan, op. cit. supra, at 479. The “mere evidence” limitation has spawned exceptions so numerous and confusion so great, in fact, that it is questionable whether it affords meaningful protection. But if its rejection does enlarge the area of permissible searches, the intrusions are nevertheless made after fulfilling the probable cause and particularity requirements of the Fourth Amendment and after the intervention of “a neutral and detached magistrate . . . .” Johnson v. United States, 333 U. S. 10, 14. The Fourth Amendment allows intrusions upon privacy-under these circumstances, and there is no viable reason to distinguish intrusions to secure “mere evidence” from intrusions to secure fruits, instrumentalities, or contraband.
  The judgment of the Court of Appeals is
  Reversed.
  Mr. Justice Black concurs in the result.
  Harris v. United States, 331 U. S. 145, 154; see also Gouled v. United States, 255 U. S. 298; United States v. Lefkowitz, 285 U. S. 452, 465-466; United States v. Rabinowitz, 339 U. S. 56, 64, n. 6; Abel v. United States, 362 U. S. 217, 234-235.
  Hayden did not appeal from his conviction. He first sought relief by an application under the Maryland Post Conviction Procedure Act which was denied without hearing. The Maryland Court of Appeals reversed and remanded for a hearing. 233 Md. 613, 195 A. 2d 692. The trial court denied relief after hearing, concluding “that the search of his home and the seizure of the articles in question were proper.” His application for federal habeas corpus relief resulted, after hearing in the District Court, in the same conclusion.
  The State claims that, since Hayden failed to raise the search and seizure question at trial, he deliberately bypassed state remedies and should be denied an opportunity to assert his claim in federal court. See Henry v. Mississippi, 379 U. S. 443; Fay v. Noia, 372 U. S. 391. Whether or not the Maryland Court of Appeals actually intended, when it reversed the state trial court’s denial of post-conviction relief, that Hayden be afforded a hearing on the merits of his claim, it is clear that the trial court so understood the order of the Court of Appeals. A hearing was held in the state courts, and the claim denied on the merits. In this circumstance, the Fourth Circuit was correct in rejecting the State’s deliberate-bypassing claim. The deliberate-bypass rule is applicable only “to an applicant who has deliberately by-passed the orderly procedure of the state courts and in so doing has forfeited his state court remedies.” Fay v. Noia, supra, 372 U. S., at 438. (Emphasis added.) But see Nelson v. California, 346 F. 2d 73, 82 (C. A. 9th Cir. 1965).
  The state postconviction court found that Mrs. Hayden “gave the policeman permission to enter the home.” The federal habeas corpus court stated it “would be justified in accepting the findings of historical fact made by Judge Sodaro on that issue but concluded that resolution of the issue would be unnecessary, because the officers were “justified in entering and searching the house for the felon, for his weapons and for the fruits of the robbery.”
  The officer was asked in the District Court whether he found the money. He answered that he did not, and stated: “By the time I had gotten down into the basement I heard someone say upstairs, 'There’s a man up here.’ ” He was asked: “What did you do then?” and answered: “By this time I had already discovered some clothing which fit the description of the clothing worn by the subject that we were looking for . . . .” It is clear from the record and from the findings that the weapons were found after or at the same time the police found Hayden.
  People v. Thayer, 63 Cal. 2d 635, 408 P. 2d 108, cert. denied, 384 U. S. 908; State v. Bisaccia, 45 N. J. 504, 213 A. 2d 185. Compare United States v. Poller, 43 F. 2d 911, 914 (C. A. 2d Cir. 1930).
  E. g., Chafee, The Progress of the Law, 1919-1922, 35 Harv. L. Rev. 673 (1922); Kamisar, The Wiretapping-Eavesdropping Problem: A Professor’s View, 44 Minn. L. Rev. 891, 914-918 (1960); Kaplan, Search and Seizure: A No-Man’s Land in the Criminal Law, 49 Calif. L. Rev. 474, 478 (1961); Comment, 45 N. C. L. Rev. 512 (1967); Comment, 66 Col. L. Rev. 355 (1966); Comment, 20 U. Chi. L. Rev. 319 (1953); Comment, 31 Yale L. J. 518 (1922). Compare, e. g., Fraenkel, Concerning Searches and Seizures, 34 Harv. L. Rev. 361 (1921); Note, 54 Geo. L. J. 593 (1966).
  This Court has approved the seizure and introduction of items having only evidential value without, however, considering the validity of the distinction rejected today. See Schmerber v. California, 384 U. S. 757; Cooper v. California, 386 U. S. 58.
  E. g., Stanford v. Texas, 379 U. S. 476, 481-485; Marcus v. Search Warrant, 367 U. S. 717, 724-729; Frank v. Maryland, 359 U. S. 360, 363-365. See generally Lasson, The History and Development of the Fourth Amendment to the United States Constitution (1937); Landynski, Search and Seizure and the Supreme Court (1966).
  Both Weeks and Adams were written by Justice Day, and joined by several of the same Justices, including Justice Holmes.
  At common law the Government did assert a superior property interest when it searched lawfully for stolen property, since the procedure then followed made it necessary that the true owner swear that his goods had been taken. But no such procedure need be followed today; the Government may demonstrate probable cause and lawfully search for stolen property even though the true owner is unknown or unavailable to request and authorize the Government to assert his interest. As to instrumentalities, the Court in Gouled allowed their seizure, not because the Government had some property interest in them (under the ancient, fictitious forfeiture theory), but because they could be used to perpetrate further crime. 255 U. S., at 309. The same holds true, of course, for “mere evidence”; the prevention of crime is served at least as much by allowing the Government to identify and capture the criminal, as it is by allowing the seizure of his instrumentalities. Finally, contraband is indeed property in which the Government holds a superior interest, but only because the Government decides to vest such an interest in itself. And while there may be limits to what may be declared contraband, the concept is hardly more than a form through which the Government seeks to prevent and deter crime.
  Gouled was decided on certified questions. The only question which referred to the Espionage Act of 1917 stated: “Are papers of . . . evidential value . . . , when taken under search warrants issued pursuant to Act of June 15, 1917, from the house or office of the person so suspected, — seized and taken in violation of the 4th amendment?” Gouled v. United States, No. 250, Oct. Term, 1920, Certificate, p. 4. Thus the form in which the case was certified made it difficult if not impossible “to limit the decision to the sensible proposition of statutory construction, that Congress had not as yet authorized the seizure of purely evidentiary material.” Chafee, op. cit. supra, at 699. The Government assumed the validity of petitioner’s argument that Entick v. Carrington, Boyd v. United States, and other authorities established the constitutional illegality of seizures of private papers for use as evidence. Gouled v. United States, supra, Brief for the United States, p. 50. It argued, complaining of the absence of a record, that the papers introduced in evidence were instrumentalities of crime. The Court ruled that the record before it revealed no government interest in the papers other than as evidence against the accused. 255 U. S., at 311.
  Significantly, Entick v. Carrington itself has not been read by the English courts as making unlawful the seizure of all papers for use as evidence. See Dillon v. O’Brien, 20 L. R. Ir. 300; Elias v. Pasmore, [1934] 2 K. B. 164. Although Dillon, decided in 1887, involved instrumentalities, the court did not rely on this fact, but rather on “the interest which the State has in a person guilty (or reasonably believed to be guilty) of a crime being brought to justice . . . .” 20 L. R. Ir., at 317.