Riley v. California

Primary tabs

LII note: The U.S. Supreme Court has now decided Riley v. California.


Does the Fourth Amendment permit police officers to perform a warrantless search of an individual’s cell phone confiscated at the time of an arrest?

Oral argument: 
April 29, 2014

In August 2009, David Riley was pulled over in San Diego, California for having expired tags on his car and a suspended driver’s license. As per police department policy, the officer impounded Riley’s car and conducted a warrantless search of the car. The officer found two handguns that were later linked to a shooting that had taken place a few weeks prior. During the arrest, the officers confiscated and rummaged through the data on Riley’s smartphone without a warrant. Some of the data on the phone linked Riley to gang activity and the shooting and was entered into evidence at the trial, where Riley was convicted on three charges. Riley argues that allowing police officers to search through data on his cell phone without a warrant is an unacceptable intrusion on personal privacy. California argues that police officers need to be able to confiscate cell phones without first obtaining a warrant for safety reasons and to prevent destruction of evidence. The Supreme Court’s decision in this case will affect the balance between those two concerns and the scope of Fourth Amendment protection available to personal technology.

Questions as Framed for the Court by the Parties 

Whether or under what circumstances the Fourth Amendment permits police officers to conduct a warrantless search of the digital contents of an individual’s cell phone seized from the person at the time of arrest.



On August 2, 2009 around 2:30 p.m., David Riley, an alleged member of the Lincoln Park gang, was parked in a San Diego neighborhood with his girlfriend and three other men. When a member of a rival gang, Mr. Webster, drove through the nearby intersection, the three men near Riley’s car fired multiple shots into Mr. Webster’s car. After Mr. Webster’s car crashed, the three nearby shooters got into Riley’s car, an Oldsmobile, and drove away. Eyewitnesses to the shooting claimed that Riley could have been one of the shooters but declined to give a definitive positive identification of Riley as one of the shooters. Police found Riley’s Oldsmobile in a known Lincoln Park gang area the next day almost completely hidden.

When Riley was pulled over on August 22, 2009 for expired registrations tags in his second car, a Lexus, San Diego Police Officer Dunnigan also found that Riley was driving with a suspended driver’s license. The San Diego Police Department’s policy is to tow and impound a vehicle after stopping a driver with a suspended license in order to prevent the driver from driving again. Additionally, policy dictates that the police must perform an inventory search of the vehicle, which in this case led to the discovery of two handguns that, through ballistic testing, were confirmed as the weapons used in the August 2nd shooting of Mr. Webster. None of this information was known by Officer Dunnigan at the time of Riley’s traffic stop.

Because of the discovery of the guns and other gang paraphernalia during the vehicle search, police placed Riley under arrest and searched his cell phone without a warrant. Search of the cell phone yielded information indicating that Riley was a member of the Lincoln Park gang; evidence included pictures, cell phone contacts, texts messages, and video clips. Included in the photos was a picture of the Oldsmobile involved in the shooting of Mr. Webster. The Petitioner moved to suppress the cell phone evidence at the trial level, but the judge permitted this evidence in both the first trial and on retrial. Ultimately, Riley was convicted on three charges and the California Court of Appeal affirmed the judgment.



This case presents the Supreme Court with the opportunity to consider whether cell phones should be subject to warrantless searches by police officers.


Amici in favor of the Petitioner argue that smart phones simply contain too much personal information to be legally searched by police without a warrant. For example, the American Library Association argues that constitutional protections will be surrendered if police can search the smart phone of every American arrested without a warrant, especially when more than half of all adults in the United States own smart phones. Smart phones, the Association argues, reveal the most private thoughts of the average American, containing extensive records of the books read, websites visited, and conversations with friends and family of the owner. Amici argue that if police are able to go through the massive amounts of data stored on most smart phones upon arrest, then police offers will utilize this data in pursuit of aggressive investigation techniques. The DKT Liberty Project adds that smart phones have become a modern repository for thoughts, and often contain intimate and intensely private information of all types. Amici further contend that smart phones are every bit as sophisticated as personal computers and need to be treated as such and can be thought of as a window into the owner’s mind. Amici argue that something so personal and extensive cannot be allowed to be confiscated and searched during routine police procedures that do not require a warrant.

The Respondent, the State of California, asserts that it is necessary for police officers to confiscate cell phones without warrants because they pose a significant threat to officers’ safety. California points to the possibility of devices being rigged to detonate remotely or explode when a specific action is carried out on the phone while in the owner’s possession. Moreover, the State argues that cell phones can be used by their owners to call for assistance, which can cause a potentially immense threat to officers as well as the public. Additionally, while the Petitioner views the sophistication of smart phones as reason not to confiscate them, the State warns that smart phones can be used to track their owners, helping those who wish to frustrate the officers’ intentions and assist the owner without the owner having actively called for backup in any way. Examination of the phone would allow officers to identify whether the phone has been weaponized or used in a way that might compromise the safety of the officers or the public. Additionally, the State contends, cell phones can be used to help police officers quickly confirm the identity of their owners, which is often an immediate concern. The State also argues that it is necessary for police officers to confiscate cell phones immediately, without a warrant, in order to preserve evidence before owners delete valuable data.



In this case, the Supreme Court will decide whether cell phones can be subject to warrantless searches incident to an arrest. The Fourth Amendment prevents unreasonable searches and seizures; however, a search incident to arrest has been ruled reasonable. This search has traditionally extended to any objects on an individual or within reach.


Petitioner Riley argues that in People v. Diaz, the California Supreme Court ruled that police officers can “rummage” through the digital contents of a smartphone during an arrest or traffic stop. Riley argues that while searches incident to arrest are an exception to the warrant requirement, the exception was granted to further the government interests of officer safety and preservation of evidence, neither of which were implicated by the digital contents of the smartphone here. Riley argues that the digital contents of a smartphone do not threaten officer safety because they are not containers which could hold harmful physical objects. Furthermore, Riley argues that a cell phone does not need to be searched in order to preserve data, because the data will still be on the phone once a warrant is obtained and steps can be taken, such as the use of a Faraday, to prevent the erasure of data. Riley also argues that limiting searches of smart phones to situations where an officer believes that the phone may contain evidence of a crime would not solve these constitutional problems. This limitation, in Riley’s view, would still allow officers to examine the content of cell phones at their discretion if they have a reasonable belief that there is evidence of a crime, and this subjectivity would not prevent violations of constitutional rights.

California counters that United States v. Robinson outlines a clear, categorical rule that allows any item in an individual’s possession at the time of arrest to be subject to search. California contends that this rule stems from the government’s interest in officer safety, and that a large body of cases allow officers to search areas that might present a danger. The State argues that over time, the search rule has evolved to allow searches incident to arrest, including the arrestee himself and the area around him. The States further argues that the bright-line Robinson rule was based on concerns for officer safety and the preservation of evidence, and that Riley ignores these two justifications. California argues that even if the rule is not applied broadly here, the cell phone in this case was subjected to a legitimate search because a cell phone can pose a safety threat to officers if it is rigged to remotely detonate a bomb or if it has been used to call for back-up. Furthermore, California asserts that preservation of evidence should be considered here, and that police officers should search cell phones to prevent the remote erasure of data and the deletion of data that is time sensitive.

Riley argues that the search of his cell phone at the police station was too remote from the time and place of his arrest to qualify as a search incident to an arrest. Riley argues that once the police have exclusive control over items they have taken from an arrestee, the items are no longer a safety hazard to the police, and are not in danger of being destroyed by the arrestee. Thus, he argues, there was no justifiable reason to search his phone without a warrant. Riley maintains that the remoteness limitation on searches incident to arrest should apply here because the officer who searched his phone at the station had no reason to do so without a warrant. Further, Riley states that while objects on an individual in police custody can be seized for administrative processing, the search here was investigative, not administrative, and thus it was unjustified.

Respondent argues that searches conducted legally at the time of arrest can be conducted later at the place of detention during a custodial arrest. California states that processing items at the station is merely part of the procedural steps taken while conducting a search incident to an arrest, and “searching” items at the station is a necessary step in that process. Thus, the State argues, once an item has been cursorily searched at the scene of an arrest, it can be re-examined in more detail later. Here, California stresses that the search on Riley’s phone at the police station was not too remote, rather, it was a step in a legitimate administrative process.


Riley argues that even if searching the digital contents of a cellphone serves a legitimate government interest, such a search is unreasonable because it violates personal privacy to an unprecedented degree. Riley emphasizes the sensitivity of information that can be contained on a phone, and asserts that phones can be viewed as a virtual warehouse or extension of one’s mind. In his view, while an arrested individual may be deprived of the privacy interest in his clothes and items on him, it does not allow the government to conduct a search of the personal information on his phone. The information that is now contained on cell phones was once contained within the safety and privacy of one’s home. Riley argues that because modern phones contain more information than could ever be carried before, unbounded searches through that extensive digital record cannot be allowed. Furthermore, the information on cell phones implicates First Amendment concerns of free expression and free association, because the search and seizure of expressive materials such as contact lists and phone call records must be particularized in order to avoid the violation of First Amendment rights. Riley argues that it is unreasonable to search personal communications incident to arrest because the search would expose protected communications to scrutiny without the proper justification provided by a warrant.

California argues that technological advances do not warrant the adoption of special rules for cell phones during searches incident to arrest. The States reiterates that an arrest itself justifies a substantial invasion of privacy while an officer is investigating a crime. Moreover, the States argues that the volume of information that an individual chooses to carry with him should not change what type of objects can be searched during an arrest. California points out that personal information carried on a cell phone is fundamentally similar to information that can be carried on pieces of paper, in photographs, in wallets, and in purses. Thus, the States contends that cell phones are an evolution in the amount of information that an individual can carry, but not in the sort of information that an individual can carry, so traditional search laws should apply to cell phones. The State also argues that there is no reason to specially limit cell phone searches incident to arrest because there is no evidence that First Amendment concerns are implicated here; the information that could be ascertained from papers on an individual is the same that could be ascertained from a phone. In sum, the States argues that this type of search does impinge important privacy interests, but is justified in the context of a custodial arrest.



In this case, the Supreme Court must consider whether cell phones can be subject to searches incident to arrest. Petitioner Riley argues that the two justifications for searches incident to arrest –- officer safety and preservation of evidence -- do not apply to the search of a cell phone. Respondent California urges a categorical rule that all items on and around an individual at the time of arrest can be part of a lawful search. Moreover, the State contends that a cell phone can pose a danger to officer security and the preservation of evidence. This case will address the scope of Fourth Amendment protection available for modern technological devices, and whether individuals have a special privacy interest in the information on their phones during an arrest.


Edited by 

Additional Resources