Amdt4.2.1 Scope of the Rights Protected by the Fourth Amendment: Overview

Fourth Amendment:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

In Harris v. United States,1 it approved as reasonable the warrantless search of a four-room apartment pursuant to the arrest of the man found there. A year later, however, a reconstituted Court majority set aside a conviction based on evidence seized by a warrantless search pursuant to an arrest and adopted the cardinal rule that, in seizing goods and articles, law enforcement agents must secure and use search warrants wherever reasonably practicable.2 This rule was set aside two years later by another reconstituted majority, which adopted the premise that the test is not whether it is reasonable to procure a search warrant, but whether the search was reasonable. Whether a search is reasonable, the Court said, must find resolution in the facts and circumstances of each case.3 However, the Court soon returned to its emphasis upon the warrant. The [Fourth] Amendment was in large part a reaction to the general warrants and warrantless searches that had so alienated the colonists and had helped speed the movement for independence. In the scheme of the Amendment, therefore, the requirement that ‘no Warrants shall issue, but upon probable cause,’ plays a crucial part.4 Therefore, the police must, whenever practicable, obtain advance judicial approval of searches and seizures through a warrant procedure.5 Exceptions to searches under warrants were to be closely contained by the rationale undergirding the necessity for the exception, and the scope of a search under one of the exceptions was similarly limited.6

During the 1970s the Court was closely divided on which standard to apply.7 For a while, the balance tipped in favor of the view that warrantless searches are per se unreasonable, with a few carefully prescribed exceptions.8 Gradually, guided by the variable-expectation-of-privacy approach to coverage of the Fourth Amendment, the Court broadened its view of permissible exceptions and of the scope of those exceptions.9 By 1992, it was no longer the case that the warrants-with-narrow-exceptions standard normally prevails over a reasonableness approach.10 Exceptions to the warrant requirement have multiplied, tending to confine application of the requirement to cases that are exclusively criminal in nature. And even within that core area of criminal cases, some exceptions have been broadened.

The most important category of exception is that of administrative searches justified by special needs beyond the normal need for law enforcement. Under this general rubric the Court has upheld warrantless searches by administrative authorities in public schools, government offices, and prisons, and has upheld drug testing of public and transportation employees.11 In all of these instances, the warrant and probable cause requirements are dispensed with in favor of a reasonableness standard that balances the government’s regulatory interest against the individual’s privacy interest; in all of these instances, the government’s interest has been found to outweigh the individual’s. The broad scope of the administrative search exception is evidenced by the fact that an overlap between law enforcement objectives and administrative special needs does not result in application of the warrant requirement; instead, the Court has upheld warrantless inspection of automobile junkyards and dismantling operations in spite of the strong law enforcement component of the regulation.12

In the law enforcement context, where search by warrant is still the general rule, there has also been some loosening of the requirement. For example, the scope of a valid search incident to arrest, once limited to areas within the immediate reach of the arrested suspect, was expanded to a protective sweep of the entire home, if arresting officers have a reasonable belief that the home harbors an individual who may pose a danger.13 The Court has also recognized that exigent circumstances may justify performing a blood test without a warrant on a motorist to determine his or her blood alcohol concentration (BAC).14 In another case, the Court shifted focus from whether exigent circumstances justified failure to obtain a warrant, to whether an officer had a reasonable belief that an exception to the warrant requirement applied.15 The Court has also held that an exigent circumstances exception applied even where the exigency arose as a result of police conduct, so long as the police conduct was reasonable in that it neither threatened to nor violated the Fourth Amendment.16

Another matter of scope that the Court has addressed is the category of persons protected by the Fourth Amendment; i.e., who constitutes the people. This phrase, the Court determined, refers to a class of persons who are part of a national community or who have otherwise developed sufficient connection with [the United States] to be considered part of that community.17 The Fourth Amendment therefore does not apply to the search and seizure by United States agents of property that is owned by a nonresident alien and located in a foreign country. The community of protected people includes U.S. citizens who go abroad, and aliens who have voluntarily entered U.S. territory and developed substantial connections with this country. There is no resulting broad principle, however, that the Fourth Amendment constrains federal officials wherever and against whomever they act.


  1.  Jump to essay-1331 U.S. 145 (1947).
  2.  Jump to essay-2Trupiano v. United States, 334 U.S. 699, 705 (1948). See also McDonald v. United States, 335 U.S. 451 (1948).
  3.  Jump to essay-3United States v. Rabinowitz, 339 U.S. 56, 66 (1950).
  4.  Jump to essay-4Chimel v. California, 395 U.S. 752, 761 (1969).
  5.  Jump to essay-5Terry v. Ohio, 392 U.S. 1, 20 (1968). In United States v. United States District Court, 407 U.S. 297, 321 (1972), Justice Powell explained that the very heart of the Amendment’s mandate is that where practical, a governmental search and seizure should represent both the efforts of the officer to gather evidence of wrongful acts and the judgment of the magistrate that the collected evidence is sufficient to justify invasion of a citizen’s private premises or conversation. Thus, what is reasonable in terms of a search and seizure derives content and meaning through reference to the warrant clause. Coolidge v. New Hampshire, 403 U.S. 443, 473–84 (1971). See also Davis v. Mississippi, 394 U.S. 721, 728 (1969); Katz v. United States, 389 U.S. 347, 356–58 (1967); Warden v. Hayden, 387 U.S. 294, 299 (1967).
  6.  Jump to essay-6Chimel v. California, 395 U.S. 752, 762–64 (1969) (limiting scope of search incident to arrest). See also United States v. United States District Court, 407 U.S. 297 (1972) (rejecting argument that it was reasonable to allow President through Attorney General to authorize warrantless electronic surveillance of persons thought to be endangering the national security); Katz v. United States, 389 U.S. 347 (1967) (although officers acted with great self-restraint and reasonably in engaging in electronic seizures of conversations from a telephone booth, a magistrate’s antecedent judgment was required); Preston v. United States, 376 U.S. 364 (1964) (warrantless search of seized automobile not justified because not within rationale of exceptions to warrant clause). There were exceptions, e.g., Cooper v. California, 386 U.S. 58 (1967) (warrantless search of impounded car was reasonable); United States v. Harris, 390 U.S. 234 (1968) (warrantless inventory search of automobile).
  7.  Jump to essay-7See, e.g., Almighty-Sanchez v. United States, 413 U.S. 266 (1973), Justices Stewart, Douglas, Brennan, and Marshall adhered to the warrant-based rule, while Justices White, Blackmun, and Rehnquist, and Chief Justice Burger placed greater emphasis upon the question of reasonableness without necessary regard to the warrant requirement. Id. at 285. Justice Powell generally agreed with the former group of Justices, id. at 275 (concurring).
  8.  Jump to essay-8E.g., G.M. Leasing Corp. v. United States, 429 U.S. 338, 352–53 (1977) (unanimous); Marshall v. Barrow’s, Inc., 436 U.S. 307, 312 (1978); Michigan v. Tyler, 436 U.S. 499, 506 (1978); Mincey v. Arizona, 437 U.S. 385, 390 (1978) (unanimous); Arkansas v. Sanders, 442 U.S. 753 (1979); United States v. Ross, 456 U.S. 798, 824–25 (1982).
  9.  Jump to essay-9E.g., Chambers v. Maroney, 399 U.S. 42 (1970) (warrantless search of automobile taken to police station); Texas v. White, 423 U.S. 67 (1975) (same); New York v. Belton, 453 U.S. 454 (1981) (search of vehicle incident to arrest); United States v. Ross, 456 U.S. 798 (1982) (automobile search at scene); Brigham City, Utah v. Stuart, 547 U.S. 398 (2006) (warrantless entry into a home when police have an objectively reasonable basis for believing that an occupant is seriously injured or imminently threatened with such injury); Michigan v. Fisher, 558 U.S. ___, No. 09-91 (2009) (applying Brigham City). On the other hand, the warrant-based standard did preclude a number of warrantless searches. E.g., Almighty-Sanchez v. United States, 413 U.S. 266 (1973) (warrantless stop and search of auto by roving patrol near border); Marshall v. Barrow’s, Inc., 436 U.S. 307 (1978) (warrantless administrative inspection of business premises); Mincey v. Arizona, 437 U.S. 385 (1978) (warrantless search of home that was homicide scene); Arizona v. Gant, 556 U.S. ___, No. 07-542 (2009) (search of vehicle incident to arrest where arrestee had no access to vehicle).
  10.  Jump to essay-10Of the Justices on the Court in 1992, only Justice Stevens frequently sided with the warrants-with-narrow-exceptions approach. See, e.g., Illinois v. Rodriguez, 497 U.S. 177, 189 (1990) (Justice Stevens joining Justice Marshall’s dissent); New Jersey v. T.L.O., 469 U.S. 325, 370 (1985) (Justice Stevens dissenting); California v. Acevedo, 500 U.S. 565, 585 (1991) (Justice Stevens dissenting).
  11.  Jump to essay-11See various headings infra under the general heading Valid Searches and Seizures Without Warrants.
  12.  Jump to essay-12New York v. Burger, 482 U.S. 691 (1987).
  13.  Jump to essay-13Maryland v. Buie, 494 U.S. 325 (1990).
  14.  Jump to essay-14See Missouri v. McNeely, 569 U.S. 141, 156 (2013) (rejecting a per se exception to the warrant requirement for BAC blood testing in suspected drunk-driving cases and requiring that exigent circumstances be evaluated under a totality of the circumstances test). Cf. Mitchell v. Wisconsin, 139 S. Ct. 2525, 2534–35 (2019) (plurality opinion) (declining to revisit the rule established in McNeely but concluding that in circumstances involving unconscious drivers, where a breath test for BAC cannot be performed, exigent circumstances generally exist to take a warrantless blood test).
  15.  Jump to essay-15Illinois v. Rodriguez, 497 U.S. 177 (1990).
  16.  Jump to essay-16Kentucky v. King,563 U.S. 452 (2011) (police justified in entering apartment after smelling burning marijuana in a hallway, knocking on apartment door, and hearing noises consistent with evidence being destroyed).
  17.  Jump to essay-17United States v. Vertigo-Urquidez, 494 U.S. 259, 265 (1990).