MR. CHIEF JUSTICE BURGER delivered the opinion of the Court.We granted certiorari in this case to decide whether a search warrant is required before federal agents may open a locked footlocker which they have lawfully seized at the time of the arrest of its owners, when there is probable cause to believe the footlocker contains contraband.(1)On May 8, 1973, Amtrak railroad officials in San Diego observed respondents Gregory Machado and Bridget Leary load a brown footlocker onto a train bound for Boston.  Their suspicions were aroused when they noticed that the trunk was unusually heavy for its size, and that it was leaking talcum powder, a substance often used to mask the odor of marihuana or hashish. Because Machado matched a profile used to spot drug traffickers, the railroad officials reported these circumstances to federal agents in San Diego, who, in turn, relayed the information, together with detailed descriptions of Machado and the footlocker, to their counterparts in Boston.When the train arrived in Boston two days later, federal narcotics agents were on hand.  Though the officers had not obtained an arrest or search warrant, they had with them a police dog trained to detect marihuana.  The agents identified Machado and Leary and kept them under surveillance as they claimed their suitcases and the footlocker, which had been Page 433 U. S. 4 transported by baggage cart from the train to the departure area.  Machado and Leary lifted the footlocker from the baggage cart, placed it on the floor and sat down on it.The agents then released the dog near the footlocker.  Without alerting respondents, the dog signaled the presence of a controlled substance inside.  Respondent Chadwick then joined Machado and Leary, and they engaged an attendant to move the footlocker outside to Chadwick's waiting automobile.  Machado, Chadwick, and the attendant together lifted the 200-pound footlocker into the trunk of the car while Leary waited in the front seat.  At that point, while the trunk of the car was still open and before the car engine had been started, the officers arrested all three.  A search disclosed no weapons, but the keys to the footlocker were apparently taken from Machado.Respondents were taken to the Federal Building in Boston; the agents followed with Chadwick's car and the footlocker.  As the Government concedes, from the moment of respondents' arrests at about 9 p.m., the footlocker remained under the exclusive control of law enforcement officers at all times.  The footlocker and luggage were placed in the Federal Building, where, as one of the agents later testified, "there was no risk that whatever was contained in the footlocker trunk would be removed by the defendants or their associates."  App. 44.  The agents had no reason to believe that the footlocker contained explosives or other inherently dangerous items, or that it contained evidence which would lose its value unless the footlocker were opened at once.  Facilities were readily available in which the footlocker could have been stored securely; it is not contended that there was any exigency calling for an immediate search.At the Federal Building an hour and a half after the arrests, the agents opened the footlocker and luggage.  They did not obtain respondents' consent; they did not secure a search warrant.  The footlocker was locked with a padlock and a Page 433 U. S. 5 regular trunk lock.  It is unclear whether it was opened with the keys taken from respondent Machado or by other means.  Large amounts of marihuana were found in the footlocker. [Footnote 1]Respondents were indicted for possession of marihuana with intent to distribute it in violation of 21 U.S.C. § 841(a)(1), and for conspiracy in violation of 21 U.S.C. § 846.  Before trial, they moved to suppress the marihuana obtained from the footlocker.  In the District Court, the Government sought to justify its failure to secure a search warrant under the "automobile exception" of Chambers v. Maroney, 399 U. S. 42 (1970), and as a search incident to the arrests.  Holding that "[w]arrantless searches are per se unreasonable, subject to a few carefully delineated and limited exceptions," the District Court rejected both justifications.  393 F. Supp. 763, 771 (Mass.1975).  The court saw the relationship between the footlocker and Chadwick's automobile as merely coincidental, and held that the double-locked, 200-pound footlocker was not part of "the area from within which [respondents] might gain possession of a weapon or destructible evidence."  Chimel v. California, 395 U. S. 752,  395 U. S. 763 (1969).A divided Court of Appeals for the First Circuit affirmed the suppression of the seized marihuana.  The court held that the footlocker had been properly taken into federal custody after respondents' lawful arrest; it also agreed that the agents had probable cause to believe that the footlocker contained a controlled substance when they opened it.  But probable cause alone was held not enough to sustain the warrantless search.  Page 433 U. S. 6 On the premise that warrantless searches are per se unreasonable unless they fall within some established exception to the warrant requirement, the Court of Appeals agreed with the District Court that the footlocker search was not justified either under the "automobile exception" or as a search incident to a lawful arrest.The Court of Appeals then responded to an argument, suggested by the Government for the first time on appeal, that movable personalty lawfully seized in a public place should be subject to search without a warrant if there exists probable cause to believe it contains evidence of a crime.  Conceding that such personalty shares some characteristics of mobility which support warrantless automobile searches, the court nevertheless concluded that a rule permitting a search of personalty on probable cause alone had not yet"received sufficient recognition by the Supreme Court outside the automobile area, or generally, for us to recognize it as a valid exception to the fourth amendment warrant requirement."532 F.2d 773, 781 (1976).  We granted certiorari, 429 U.S. 814 (1976).  We affirm.(2)In this Court, the Government again contends that the Fourth Amendment Warrant Clause protects only interests traditionally identified with the home. [Footnote 2]  Recalling the colonial writs of assistance, which were often executed in searches of private dwellings, the Government claims that the Warrant Clause was adopted primarily, if not exclusively, in response to unjustified intrusions into private homes on the authority of general warrants.  The Government argues there is no evidence that the Framers of the Fourth Amendment intended Page 433 U. S. 7 to disturb the established practice of permitting warrantless searches outside the home, or to modify the initial clause of the Fourth Amendment by making warrantless searches supported by probable cause per se unreasonable.Drawing on its reading of history, the Government argues that only homes, offices, and private communications implicate interests which lie at the core of the Fourth Amendment.  Accordingly, it is only in these contexts that the determination whether a search or seizure is reasonable should turn on whether a warrant has been obtained.  In all other situations, the Government contends, less significant privacy values are at stake, and the reasonableness of a government intrusion should depend solely on whether there is probable cause to believe evidence of criminal conduct is present.  Where personal effects are lawfully seized outside the home on probable cause, the Government would thus regard searches without a warrant as not "unreasonable."We do not agree that the Warrant Clause protects only dwellings and other specifically designated locales.  As we have noted before, the Fourth Amendment "protects people, not places," Katz v. United States, 389 U. S. 347,  389 U. S. 351 (1967); more particularly, it protects people from unreasonable government intrusions into their legitimate expectations of privacy.  In this case, the Warrant Clause makes a significant contribution to that protection.  The question, then, is whether a warrantless search in these circumstances was unreasonable. [Footnote 3](3)It cannot be doubted that the Fourth Amendment's commands grew in large measure out of the colonists' experience Page 433 U. S. 8 with the writs of assistance and their memories of the general warrants formerly in use in England.  These writs, which were issued on executive, rather than judicial, authority, granted sweeping power to customs officials and other agents of the King to search at large for smuggled goods.  Though the authority to search granted by the writs was not limited to the home, searches conducted pursuant to them often were carried out in private residences.  See generally Stanford v. Texas, 379 U. S. 476,  379 U. S. 481-485 (1965); Marcus v. Search Warrant, 367 U. S. 717,  367 U. S. 724-729 (1961); Frank v. Maryland, 359 U. S. 360 (1959).Although the searches and seizures which deeply concerned the colonists, and which were foremost in the minds of the Framers, were those involving invasions of the home, it would be a mistake to conclude, as the Government contends, that the Warrant Clause was therefore intended to guard only against intrusions into the home.  First, the Warrant Clause does not, in terms, distinguish between searches conducted in private homes and other searches.  There is also a strong historical connection between the Warrant Clause and the initial clause of the Fourth Amendment, which draws no distinctions among "persons, houses, papers, and effects" in safeguarding against unreasonable searches and seizures.  See United States v. Rabinowitz, 339 U. S. 56,  339 U. S. 68 (1950) (Frankfurter, J., dissenting).Moreover, if there is little evidence that the Framers intended the Warrant Clause to operate outside the home, there is no evidence at all that they intended to exclude from protection of the Clause all searches occurring outside the home.  The absence of a contemporary outcry against warrantless searches in public places was because, aside from searches incident to arrest, such warrantless searches were not a large issue in colonial America.  Thus, silence in the historical record tells us little about the Framers' attitude toward application of the Warrant Clause to the search of respondents' Page 433 U. S. 9 footlocker. [Footnote 4]  What we do know is that the Framers were men who focused on the wrongs of that day, but who intended the Fourth Amendment to safeguard fundamental values which would far outlast the specific abuses which gave it birth.Moreover, in this area, we do not write on a clean slate.  Our fundamental inquiry in considering Fourth Amendment issues is whether or not a search or seizure is reasonable under all the circumstances.  Cooper v. California, 386 U. S. 58 (1967).  The judicial warrant has a significant role to play, in that it provides the detached scrutiny of a neutral magistrate, which is a more reliable safeguard against improper searches than the hurried judgment of a law enforcement officer "engaged in the often competitive enterprise of ferreting out crime."  Johnson v. United States, 333 U. S. 10,  333 U. S. 14 (1948).  Once a lawful search has begun, it is also far more likely that it will not exceed proper bounds when it is done pursuant to a judicial authorization "particularly describing the place to be searched and the persons or things to be seized."  Further, a warrant assures the individual whose property is searched or seized of the lawful authority of the executing officer, his need to search, and the limits of his power to search.  Camara v. Municipal Court, 387 U. S. 523,  387 U. S. 532 (1967).Just as the Fourth Amendment "protects people, not places," the protections a judicial warrant offers against erroneous Page 433 U. S. 10 governmental intrusions are effective whether applied in or out of the home.  Accordingly, we have held warrantless searches unreasonable, and therefore unconstitutional, in a variety of settings. [Footnote 5]  A century ago, Mr. Justice Field, speaking for the Court, included within the reach of the Warrant Clause printed matter traveling through the mails within the United States:"Letters and sealed packages of this kind in the mail are as fully guarded from examination and inspection, except as to their outward form and weight, as if they were retained by the parties forwarding them in their own domiciles.  The constitutional guaranty of the right of the people to be secure in their papers against unreasonable searches and seizures extends to their papers, thus closed against inspection, wherever they may be.  Whilst in the mail, they can only be opened and examined under like warrant, issued upon similar oath or affirmation, particularly describing the thing to be seized, as is required when papers are subjected to search in one's own household."Ex parte Jackson, 96 U. S. 727,  96 U. S. 733 (1878).  We reaffirmed Jackson in United States v. Van Leeuwen, 397 U. S. 249 (1970), where a search warrant was obtained to open two packages which, on mailing, the sender had declared contained only coins.  Judicial warrants have been required for other searches conducted outside the home.  E.g., Katz v. United States, 389 U. S. 347 (1967) (electronic interception of conversation in public telephone booth); Coolidge v. New Hampshire, 403 U. S. 443 (1971) (automobile on private Page 433 U. S. 11 premises); Preston v. United States, 376 U. S. 364 (1964) (automobile in custody); United States v. Jeffers, 342 U. S. 48 (1951) (hotel room); G. M. Leasing Corp. v. United States, 429 U. S. 338 (1977) (office); Mancusi v. DeForte, 392 U. S. 364 (1968) (office).  These cases illustrate the applicability of the Warrant Clause beyond the narrow limits suggested by the Government.  They also reflect the settled constitutional principle, discussed earlier, that a fundamental purpose of the Fourth Amendment is to safeguard individuals from unreasonable government invasions of legitimate privacy interests, [Footnote 6] and not simply those interests found inside the four walls of the home.  Wolf v. Colorado, 338 U. S. 25,  338 U. S. 27 (1949).In this case, important Fourth Amendment privacy interests were at stake.  By placing personal effects inside a double-locked footlocker, respondents manifested an expectation that the contents would remain free from public examination.  No less than one who locks the doors of his home against intruders, one who safeguards his personal possessions in this manner is due the protection of the Fourth Amendment Warrant Clause.  There being no exigency, it was unreasonable for the Government to conduct this search without the safeguards a judicial warrant provides.(4)The Government does not contend that the footlocker's brief contact with Chadwick's car makes this an automobile search, but it is argued that the rationale of our automobile Page 433 U. S. 12 search cases demonstrates the reasonableness of permitting warrantless searches of luggage; the Government views such luggage as analogous to motor vehicles for Fourth Amendment purposes.  It is true that, like the footlocker in issue here, automobiles are "effects" under the Fourth Amendment, and searches and seizures of automobiles are therefore subject to the constitutional standard of reasonableness.  But this Court has recognized significant differences between motor vehicles and other property which permit warrantless searches of automobiles in circumstances in which warrantless searches would not be reasonable in other contexts.  Carroll v. United States, 267 U. S. 132 (1925); Preston v. United States, supra at  376 U. S. 366-367; Chambers v. Maroney, 399 U. S. 42 (1970).  See also South Dakota v. Opperman, 428 U. S. 364,  428 U. S. 367 (1976).Our treatment of automobiles has been based in part on their inherent mobility, which often makes obtaining a judicial warrant impracticable.  Nevertheless, we have also sustained"warrantless searches of vehicles . . . in cases in which the possibilities of the vehicle's being removed or evidence in it destroyed were remote, if not nonexistent."Cady v. Dombrowski, 413 U. S. 433,  413 U. S. 441-442 (1973); accord, South Dakota v. Opperman, supra at  428 U. S. 367; see Texas v. White, 423 U. S. 67 (1975); Chambers v. Maroney, supra; Cooper v. California, 386 U. S. 58 (1967).The answer lies in the diminished expectation of privacy which surrounds the automobile:"One has a lesser expectation of privacy in a motor vehicle because its function is transportation and it seldom serves as one's residence or as the repository of personal effects. . . .  It travels public thoroughfares where both its occupants and its contents are in plain view."Cardwell v. Lewis, 417 U. S. 583,  417 U. S. 590 (1974) (plurality opinion).  Other factors reduce automobile privacy."All States require Page 433 U. S. 13 vehicles to be registered and operators to be licensed.  States and localities have enacted extensive and detailed codes regulating the condition and manner in which motor vehicles may be operated on public streets and highways."Cady v. Dombrowski, supra, at  413 U. S. 441.  Automobiles periodically undergo official inspection, and they are often taken into police custody in the interests of public safety.  South Dakota v. Opperman, supra at  428 U. S. 368.The factors which diminish the privacy aspects of an automobile do not apply to respondents' footlocker.  Luggage contents are not open to public view, except as a condition to a border entry or common carrier travel; nor is luggage subject to regular inspections and official scrutiny on a continuing basis.  Unlike an automobile, whose primary function is transportation, luggage is intended as a repository of personal effects.  In sum, a person's expectations of privacy in personal luggage are substantially greater than in an automobile.Nor does the footlocker's mobility justify dispensing with the added protections of the Warrant Clause.  Once the federal agents had seized it at the railroad station and had safely transferred it to the Boston Federal Building under their exclusive control, there was not the slightest danger that the footlocker or its contents could have been removed before a valid search warrant could be obtained. [Footnote 7]  The initial seizure and detention of the footlocker, the validity of which respondents do not contest, were sufficient to guard against any risk that evidence might be lost.  With the footlocker safely immobilized, it was unreasonable to undertake the additional and greater intrusion of a search without a warrant. [Footnote 8] Page 433 U. S. 14Finally, the Government urges that the Constitution permits the warrantless search of any property in the possession of a person arrested in public, so long as there is probable cause to believe that the property contains contraband or evidence of crime.  Although recognizing that the footlocker was not within respondents' immediate control, the Government insists that the search was reasonable because the footlocker was seized contemporaneously with respondents' arrests, and was searched as soon thereafter as was practicable.  The reasons justifying search in a custodial arrest are quite different.  When a custodial arrest is made, there is always some danger that the person arrested may seek to use a weapon, or that evidence may be concealed or destroyed.  To safeguard himself and others, and to prevent the loss of evidence, it has been held reasonable for the arresting officer to conduct a prompt, warrantless"search of the arrestee's person and the area 'within his immediate control' -- construing that phrase to mean the area from within which he might gain possession of a weapon or destructible evidence."Chimel v. California, 395 U.S. at  395 U. S. 763.  See also Terry v. Ohio, 392 U. S. 1 (1968).  Such searches may be conducted without a warrant, and they may also be made whether or not there is probable cause to believe that the person arrested may have a weapon or is about to destroy evidence.  The potential dangers lurking in Page 433 U. S. 15 all custodial arrests make warrantless searches of items within the "immediate control" area reasonable without requiring the arresting officer to calculate the probability that weapons or destructible evidence may be involved.  United States v. Robinson, 414 U. S. 218 (1973); Terry v. Ohio, supra.  However, warrantless searches of luggage or other property seized at the time of an arrest cannot be justified as incident to that arrest either if the "search is remote in time or place from the arrest," Preston v. United States, 376 U.S. at  376 U. S. 367, or no exigency exists.  Once law enforcement officers have reduced luggage or other personal property not immediately associated with the person of the arrestee to their exclusive control, and there is no longer any danger that the arrestee might gain access to the property to seize a weapon or destroy evidence, a search of that property is no longer an incident of the arrest. [Footnote 9]Here, the search was conducted more than an hour after federal agents had gained exclusive control of the footlocker and long after respondents were securely in custody; the search therefore cannot be viewed as incidental to the arrest or as justified by any other exigency.  Even though on this record the issuance of a warrant by a judicial officer was reasonably predictable, a line must be drawn.  In our view, when no exigency is shown to support the need for an immediate search, the Warrant Clause places the line at the point where the property to be searched comes under the exclusive dominion of police authority.  Respondents were therefore entitled to the protection of the Warrant Clause with the Page 433 U. S. 16 evaluation of a neutral magistrate, before their privacy interests in the contents of the footlocker were invaded. [Footnote 10]Accordingly, the judgment isAffirmed
U.S. Supreme CourtUnited States v. Chadwick, 433 U.S. 1 (1977)United States v. ChadwickNo. 75-1721Argued April 26, 1977Decided June 21, 1977433 U.S. 1SyllabusWhen respondents arrived by train in Boston from San Diego, they were arrested at their waiting automobile by federal narcotics agents, who had been alerted that respondents were possible drug traffickers.  A double-locked footlocker, which respondents had transported on the train and which the agents had probable cause to believe contained narcotics, had been loaded in the trunk of the automobile.  Respondents, together with the automobile and footlocker, which was admittedly under the agents' exclusive control, were then taken to the Federal Building in Boston.  An hour and a half after the arrests, the agents opened the footlocker without respondents' consent or a search warrant, and found large amounts of marihuana in it.  Respondents were subsequently indicted for possession of marihuana with intent to distribute it.  The District Court granted their pretrial motion to suppress the marihuana obtained from the footlocker, holding that warrantless searches are per se unreasonable under the Fourth Amendment unless they fall within some established exception to the warrant requirement, and that the footlocker search was not justified under either the "automobile exception" or as a search incident to a lawful arrest; the Court of Appeals affirmed.Held:  Respondents were entitled to the protection of the Warrant Clause of the Fourth Amendment, with the evaluation Page 433 U. S. 2 of a neutral magistrate, before their privacy interests in the contents of the footlocker were invaded.  Pp.  433 U. S. 6-16.(a) A fundamental purpose of the Fourth Amendment is to safeguard individuals from unreasonable government invasions of legitimate privacy interests, and not simply those interests inside the four walls of the home.  Pp.  433 U. S. 6-11.(b) By placing personal effects inside a double-locked footlocker, respondents manifested an expectation that the contents would remain free from public examination, and, no less than one who locks the doors of his home against intruders, one who safeguards his personal possessions in this manner is due the protection of the Fourth Amendment's Warrant Clause; since there was no exigency calling for an immediate search, it was unreasonable for the Government to conduct the search without the safeguards a judicial warrant provides.  P.  433 U. S. 11.(c) The footlocker search was not justified under the "automobile exception," since a person's expectations of privacy in personal luggage are substantially greater than in an automobile.  In this connection, the footlocker's mobility did not justify dispensing with a search warrant, because, once the federal agents had seized the footlocker at the railroad station and safely transferred it to the Federal Building under their exclusive control, there was not the slightest danger that it or its contents could have been removed before a valid search warrant could be obtained.  Pp.  433 U. S. 11-13.(d) Nor was the footlocker search justified as a search incident to a lawful arrest, where the search was remote in time or place from the arrest and no exigency existed, the search having been conducted more than an hour after the federal agents had gained exclusive control of the footlocker and long after respondents were securely in custody.  Pp.  433 U. S. 14-16.532 F.2d 773, affirmed.BURGER, C.J., delivered the opinion of the Court, in which BRENNAN, STEWART, WHITE, MARSHALL, POWELL, and STEVENS, JJ., joined.  BRENNAN, J., filed a concurring opinion, post, p.  433 U. S. 16.  BLACKMUN, J., filed a dissenting opinion, in which REHNQUIST, J., joined, post, p.  433 U. S. 17. Page 433 U. S. 3