Phone SeizedUnited StatesDo police need a warrant to search my phone?
Do police need a warrant to search my phone?
What you must do, what you can refuse, and what they can do
Every claim below links to the source it comes from, with the wording quoted so you can check it yourself.
What they can do
A power the law gives them over you or your device.
Riley says that “other case-specific exceptions may still justify a warrantless search of a particular phone”, referring to “the exigencies of the situation” that “make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment”.
Unlike the search-incident-to-arrest exception, the exigent circumstances exception requires a court to examine whether an emergency justified a warrantless search in each particular case.
Riley v. California, 573 U.S. 373 (2014)
“other case-specific exceptions may still justify a warrantless search of a particular phone—the exigencies of the situation—make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment—The critical point is that, unlike the search incident to arrest exception, the exigent circumstances exception requires a court to examine whether an emergency justified a warrantless search in each particular case.”
Read it at law.cornell.eduquote checked 2026-09-08
Rule 41(e)(2)(B) says that a warrant under Rule 41(e)(2)(A) may authorize the seizure of electronic storage media or the seizure or copying of electronically stored information, and that, unless otherwise specified, the warrant authorizes a later review of the media or information consistent with the warrant.
Fed. R. Crim. P. 41(e)(2)(B)
“A warrant under Rule 41(e)(2)(A) may authorize the seizure of electronic storage media or the seizure or copying of electronically stored information. Unless otherwise specified, the warrant authorizes a later review of the media or information consistent with the warrant.”
Read it at law.cornell.eduquote checked 2026-09-08
Limits on them
A rule that constrains them, or a remedy you can use.
Riley says that what police must do before searching a cell phone seized incident to an arrest is “get a warrant”.
Riley v. California, 573 U.S. 373 (2014)
“Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple—get a warrant.”
Read it at law.cornell.eduquote checked 2026-09-08
The Fourth Amendment says that 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.
U.S. Constitution, 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.”
Read it at law.cornell.eduquote checked 2026-09-08
Rule 41(e)(2)(A) says that, except for a tracking-device warrant, the warrant must identify the person or property to be searched, identify any person or property to be seized, and designate the magistrate judge to whom it must be returned.
Fed. R. Crim. P. 41(e)(2)(A)
“Except for a tracking-device warrant, the warrant must identify the person or property to be searched, identify any person or property to be seized, and designate the magistrate judge to whom it must be returned.”
Read it at law.cornell.eduquote checked 2026-10-02
Federal law — and where it doesn’t reach
This page describes federal constitutional law under the Fourth Amendment, as the U.S. Supreme Court interpreted it in Riley v. California (2014). Related questions that Riley’s rule does not itself answer — such as compelled unlocking and border searches — are covered on the sibling pages instead of being folded into this one.
The rule Riley set
The Supreme Court’s own words on what has to happen before police search a cell phone taken from someone they arrest: what police “must do before searching a cell phone seized incident to an arrest is accordingly simple—get a warrant.”
The Court said that “Cell phones differ in both a quantitative and a qualitative sense from other objects that might be kept on an arrestee’s person.” It also said: “With all they contain and all they may reveal, they hold for many Americans ‘the privacies of life’”.
The exception Riley didn’t erase
The Court said that “other case-specific exceptions may still justify a warrantless search of a particular phone”. It referred to “the exigencies of the situation” that “make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment,” and said that “unlike the search incident to arrest exception, the exigent circumstances exception requires a court to examine whether an emergency justified a warrantless search in each particular case.”
What a valid warrant has to say
The Fourth Amendment says that 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.”
Federal Rule of Criminal Procedure 41(e)(2)(A) says that, “[e]xcept for a tracking-device warrant, the warrant must identify the person or property to be searched, identify any person or property to be seized, and designate the magistrate judge to whom it must be returned.” Rule 41(e)(2)(B) says that “A warrant under Rule 41(e)(2)(A) may authorize the seizure of electronic storage media or the seizure or copying of electronically stored information. Unless otherwise specified, the warrant authorizes a later review of the media or information consistent with the warrant.”
Location history is a different question
Riley is about searching a cell phone seized incident to an arrest. Carpenter v. United States (2018) concerned cell-site location information (CSLI). In a footnote, the Court wrote: “It is sufficient for our purposes today to hold that accessing seven days of CSLI constitutes a Fourth Amendment search.” The opinion also said: “Our decision today is a narrow one. We do not express a view on matters not before us: real-time CSLI or ‘tower dumps’ (a download of information on all the devices that connected to a particular cell site during a particular interval).” Carrier and cloud-account data is covered on Cloud and carrier data, not here.
Read the opinions
Both rulings are worth reading in full rather than taking a summary’s word for it: Riley v. California and Carpenter v. United States.
Last reviewed . Next review due . No lawyer has reviewed this page — see [email protected] if you think something here is wrong.