search warrant

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A search warrant is a warrant signed by a judge or magistrate authorizing a law enforcement officer to conduct a search on a certain person, a specified place, or an automobile for criminal evidence

A search warrant usually is the prerequisite of a search, which is designed to protect individuals’ reasonable expectation of privacy against unreasonable governmental physical trespass or other intrusion. The origin of this right is from the  4th Amendment of the U.S. Constitution to protect people from unlawful government searches and seizures.

The Amendment reads: “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 warrant 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.”

Search warrant requirements

Probable cause: The officer should give reasonable information to support the possibility that the evidence of illegality will be found. Such information may come from the officer’ personal observations or that of an informant. If the warrant lacks accurate information as to what will be searched, the search is unlawful. See Groh v. Ramirez, 540 U.S. 551 (2004).

Particularity: The warrant should describe the place to be searched with particularity. See United States v. Grubbs, 547 U.S. 90 (2006). 

Signed by a “neutral and detached” magistrate or judge. See Coolidge v. New Hampshire, 403 U.S. 443 (1971).

Execution of Warrants

Object: The warrant should be executed by government officers (i.e., police officers or government officials like firepersons) to individuals. Private citizens cannot execute it. 

Timing: If an unreasonable delay occurs, causing the warrant not timely executed, the grounds that probable cause may disappear.

The warrant usually does not execute at night. Under federal law, it should occur between 6:00 a.m. and 10:00 p.m. except in some special circumstances. See §41 Fed. R. Civ. P


Knock-and-announce rule: When searching a certain place, an officer must knock and announce authority and purpose before entering, and should wait for a reasonable time or be refused admittance before using force to enter. 

Knock-and-announce rule “forms a part of the Fourth Amendment reasonableness inquiry.” See Wilson v. Arkansas, 514 U.S. 927 (1995).

Waiting time could just be several seconds or not required, if the officer has reasonable fear or suspicion that evidence will be destroyed, or the investigation will get inhibited. See Richards v. Wisconsin, 520 U.S. 385 (1997).

Failure to knock and announce will not cause the suppression of evidence.


During conduction of a search, the officer cannot search the places and individuals not listed on the warrant. For instance, if the fireperson was required to go to the basement to find the cause of fire, he went upstairs to find contraband. The contraband may be suppressed as it’s out of scope. However, the officer may detain or arrest anyone present during the search if they find sufficient evidence even if that person was in the list.

Exceptions to warrants

Evidence obtained without a valid warrant should be excluded. The Supreme Court in Katz v. United States, 389 U.S. 347 (1967) held that “searches conducted outside the judicial process, without prior approval are prohibited under the Fourth Amendment, with a few detailed exceptions.” Following are exceptions permit warrantless search.

Plain view doctrine:  

  • Private view: If an officer is lawfully on the premises or stop the vehicle for a lawful purpose, and “the incriminating character of the item is immediately apparent,” the officers can seize that in plain view, even if it is not on the list of search warrants. If the officer. See Horton v. California, 496 U.S. 128 (1990).
  • Public view: Since individuals have no reasonable expectation of privacy in things exposed to the public, items in public view may be seized without a warrant.

Exigent circumstancesOfficers will take immediate actions to secure the place to obtain time to get a warrant or just search warrantless, if they believe that failing to do so will cause the destruction of evidence, threaten public safety, or fleeing. See Illinois v. McArthur, 531 U.S. 326 (2001). If the exigency is caused by officers, the search violates the 4th Amendment. See Kentucky v. King, 563 U.S. 131 (2011).

Hot pursuit: Officers can arrest and search individuals who are suspected of committing a felony. For the pursuit, officers can enter any property to search and seize evidence without warrants. If the crime is not a felony, the exception cannot be applied. See Welsh v. Wisconsin, 466 U.S. 740 (1984).

Emergency situations: It’s applied to avoid the destruction of evidence, protect officers or the public, or inhibit suspects to flee. Whether an emergency exists is determined objectively from the officer's side.

Automobiles: If the officer has probable cause to believe that the automobile contains evidence of a crime or contraband before the automobile is searched, they can search automobiles, including the trunk and luggage, or other containers which may reasonably contain evidence or contrabands, without a warrant. See Caroll v. United States, 267 U.S. 132 (1925)

Scope: motor, trailers, boats, airplanes, and other transportation.

Consent: A third party with possessory rights of the property may have authority to consent to a search if consent is voluntarily given. 

Voluntary: If the consent was given under threats, it’s invalid. To determine whether the consent was valid, courts may evaluate the circumstances when consent was made. For instance, if the officer acquired the consent because they erroneously stated that they have a warrant, the consent given in reliance on that statement does not constitute consent. See Bumper v. North Carolina, 391 U.S. 543, 549 (1968). While failing to disclose the right to withhold consent will not cause the consent invalid. See Schneckloth v. Bustamonte, 412 U.S. 218, 233 (1973).

Authority: The property should be legally owned, occupied or jointly controlled by the third party. See Frazier v. Cupp, 394 U.S. 731, 740 (1969).

Scope: Usually it’s limited to the consent, but sometimes may extend to reasonable areas. See Florida v. Jimeno, 500 U.S. 248, 252 (1991).

Administrative search: It is different from criminal investigation, which aims to search evidence of a regulatory violation or for public interest. See Camara v. Mun. Court of San Francisco, 387 U.S. 523, 533 (1967). There are some administrative searches which needn’t warrants, like vehicle checkpoints and roadblocks, factory or inventory searches, detention of a traveler, cause of fire searches, and so on.

Stop and frisk: If officers have reasonable suspicion that a crime is occurring, they can stop a suspect for weapons to ensure their safety.


A search incident to an arrest may not require a warrant. If the officer just searches a suspect's immediate surroundings to prevent destruction of evidence or secure safety of himself or herself or nearby people. See Warden v. Hayden, 387 US. 294 (1967).

Legitimacy: Arrest must be lawful and officers have reasonable belief that the automobile contains evidence of the offense of arrest. If the search precedes the arrest, it’s illegal.

Time & area: Search must be contemporaneous in time and place with the arrest.

Scope: the person and his wingspan no matter if it's an open or closed space, locked or unlocked items.

Exception: Need exigent circumstances or search warrant to search contents of a cell phone

Some special types of warrants

Anticipatory warrants: When a police officer is issued a search warrant for contraband or evidence, they are not required to believe that contraband is in a certain place to be searched. Once probable cause of a future triggering condition likely occurs, finding contraband or evidence of a crime in that place turn out to be possible, such a warrant becomes valid. See United States v. Grubbs, supra, 547 U.S. 90 (2006)

Third-party premises: police officers even can search the place of a person who is not suspected of a crime. See Zurcher v. Stanford Daily, 436 U.S. 547 (1978).

Warrants for electronically stored information: Rule 41(e)(2)(A)of Federal Rules of Criminal Procedures authorizes police officers the right to search “electronic storage media” or “copying of electronically stored information” with search warrant. officers can copy seized material for later review. 

Post-Search Procedural Safeguards

Rule 41(f)(1) of the Federal Rules of Criminal Procedure discusses the federal requirements for returning a warrant. Most jurisdictions impose additional post-search procedural safeguards. For example, many jurisdictions require officers to return a copy of the search warrant to the judge after executing it. This return copy must include information about the search, including a list of what was seized. Similarly, most jurisdictions require officers to give a receipt for seized property.

[Last updated in May of 2022 by the Wex Definitions Team

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