Next on the Stand, Alexa: The Constitutionality of Using Smart Devices in Court

John Bernans, Associate Member, University of Cincinnati Law Review

The Fourth Amendment states “the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.”[1] In recent years, “smart technology” and advances in artificial intelligence have cast shadows on the balance between privacy and security. An Arkansas murder investigation recently brought this issue to the forefront. James Andrew Bates was accused of killing his friend Victor Collins.[2] Bates invited Collins over for a night of football and drinking and found Collins dead the following morning. Prosecutors requested the recordings from Bates’ “Amazon Echo.” The smart device has the ability to order goods, play music, and send messages by responding to its owner’s verbal commands. Investigators believed evidence from what had unfolded that night could be found within the recorded files of the device. This case is the first of its kind. Looking at Fourth Amendment jurisprudence, law enforcement cannot take files off these smart devices without a warrant. Any warrantless search or forced removal of information would violate a citizen’s reasonable expectations of privacy under the Fourth Amendment.

The Foundation of the Fourth Amendment’s Search & Seizure Jurisprudence

When an individual has a subjective expectation of privacy and society is prepared to recognize this expectation as “reasonable,” the Supreme Court has held any search that violates this expectation is a violation of the Fourth Amendment.[3] Katz v. United States was the first case to hold that oral statements were subject to the Fourth Amendment’s search and seizure protections.[4] In Katz, the defendant was indicted on federal charges for transmitting betting information by telephone from Los Angeles to Miami and Boston.[5] During the investigation, the prosecution recorded his phone conversations by placing a wiretap device on the outside of a phone booth.[6] The Supreme Court ultimately held that the Fourth Amendment protects people rather than places.[7] The Court stated “[w]hat a person seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.”[8] In extending the Fourth Amendment to oral statements, the Supreme Court used a two-prong test.[9] Justice Harlan articulated an individual’s actions should be protected “when a person has exhibited an actual (subjective) expectation of privacy, and the expectation is one that society is prepared to accept as reasonable.”[10]

The Court has since held that there are limits to an individual’s reasonable expectation of privacy.[11] In Smith v. Maryland, the Court held that a pen register that was installed on an individual’s phone did not violate the Fourth Amendment.[12] The Court permitted the installation of the pen register because the device (1) did not acquire the contents of the communication; (2) only revealed data already known to be public; and (3) the individual voluntarily signed up with the phone company.[13] Together, the Katz and Smith cases can be read to hold that generally, when an individual maintains a subjective expectation of privacy that society deems reasonable, the Fourth Amendment will protect oral statements.

An Age of New Technology

“It would be foolish to contend the degree of privacy secured to citizens by the Fourth Amendment has been entirely unaffected by the advance of technology.”[14] The Court has held that “to withdraw protection of this minimum expectation [of privacy] would be to permit police technology to erode the privacy guaranteed by the Fourth Amendment.”[15] In Kyllo v. United States, police used thermal imaging technology to detect heat emitting from a suspected marijuana greenhouse.[16] The Supreme Court held that the use of the technology without a warrant constituted an unlawful search and deemed it unconstitutional.[17] It reasoned that because the technology revealed intimate details of the home, using the technology without a warrant intruded on the occupants’ reasonable expectation of privacy.[18]  The Supreme Court applied a similar analysis to an individuals’ cellphone.[19] In Riley v. California, law enforcement pulled over the petitioner for expired tags and arrested him for driving under a suspended license.[20] During a routine search of his vehicle, police found his cell phone and searched the device without a warrant.[21] Law enforcement found picture and text message evidence that implicated the petitioner in an earlier gang-related shooting.[22] The Court reasoned that the search was unreasonable because the phone posed no threat to officer safety and was in no danger of destruction after it was confiscated.[23] The Court held “modern [technology], as a category, implicate privacy concerns far beyond those implicated by a search of a cigarette pack, a wallet, or a purse.”[24] “With that [technologies] contain and all they may reveal, [devices] hold for many Americans ‘the privacies of life.’”[25] Due to the intimate information contained in “smart devices,” the Supreme Court held that without a warrant, searches of these cell phones are unconstitutional.[26]

The Balance Between Privacy and Security

Applying Fourth Amendment jurisprudence, law enforcement cannot search “smart devices” that are discovered incident to an arrest without first obtaining a specific warrant for that device. In the balance between personal privacy and community security, the Fourth Amendment leans towards privacy. The Katz test laid down framework that can be directly applied to the search of a “smart device” like an Amazon Echo, Google Home, or Amazon Alexa. The first prong mandates a person must have an actual, subjective expectation of privacy.[27] When a customer buys a smart device, they do not expect the information that they put on the device to go public. Everything from personal communications, bank statements, and intimate thoughts can be found on these devices. An individual would not put such sensitive information on a device if they believed that law enforcement could immediately search it without a warrant. This expectation of privacy is one that society is prepared to recognize as “reasonable.” Due to the pervasive nature of this technology, the majority of the nation can recognize the importance of this expectation. As the Supreme Court estimated in Riley, approximately ninety-percent of citizens have some type of cell phone or technological device.[28]

The reasoning of Smith and the disclosure of information to your phone company could challenge this argument. The case of the Arkansas murder can be distinguished from Smith. In Smith, the Court ruled there was no reasonable expectation of privacy because the petitioner knew or should have known that his data would be disclosed to the phone company.[29] However, the law enforcement action in Smith was upheld because a pen register did not reveal the content of communication.[30] Customers recognize phone companies have access to what numbers they dial but they do not expect the nature of their calls and details of such to be saved by the phone company and subsequently turned over to police. Secondly, the data that could be revealed on the smart devices are intimate details that are not already known to the public. Lastly, while it could be argued that the customer voluntarily purchased the device, they did not sign up for the possibility that their personal and intimate information to be made public or available to law enforcement. Smith and the Arkansas case can be distinguished because phone numbers and individual dials are far less personal than the content and nature of one’s calls and personal information.

Using the reasoning of Katz and Smith, the Supreme Court has held that due to the nature of the information found on smart devices and the potential for its exposure, a warrantless search of such a device is unconstitutional. In the Kyllo case, the government argued that a search was constitutional because it did not “detect private activities occurring in private areas.”[31] These devices hold some of the most personal and intimate details of a person’s life that occur in private areas. An Amazon Echo has the potential to hold someone’s address, bank statements, prescriptions, alcohol or drug abuse information, political agendas, romantic details, and religious beliefs.[32] The fact that technology now allows an individual to carry such information in their hand does not make the information less worthy of the protection established by the Fourth Amendment. Due to the sensitive nature of the information contained in these devices and the susceptibility for abuse, the Court has consistently sent the same message when it comes to searching technological devices – in addition to a warrant required to search a home, a separate warrant would be needed in order to search a smart device.[33]


The Supreme Court established when an individual has a reasonable expectation of privacy and it is an expectation that society is ready to accept, a warrantless search of a device is unconstitutional. When analyzing the search of a smart device, an individual expects that their intimate details will not be exposed when buying such a device. Due to the pervasive nature of phones in society, it is an expectation that society is ready to accept. The holding in Smith does not apply to smart devices due to the type of information that is being exposed. Furthermore, due to the nature and details that could be exposed by such a search, the Supreme Court would most likely hold a warrant is needed. Therefore, if the search of a smart device case came before the Court, they would rule that that a warrant is needed even if the device is discovered incident to an arrest.

[1] U.S. Const. Amend. IV

[2] Eliot C. McLaughlin, Suspects Oks Amazon to hand over Echo recordings in murder case, 2017,

[3] Katz v. United States, 88 S.Ct. 507, 516 (1967)

[4] Id. at 512

[5] Id. at 509

[6] Id.

[7] Id. at 511

[8] Id.

[9] Id. at 515

[10] Id. at 516

[11] See generally Smith v. Maryland, 99 S.Ct 2577 (1979)

[12] Id. at 2581

[13] Id.

[14] Kyllo v. United States, 121 S.Ct. 2038, 2043 (2001)

[15] Id. at 2042

[16] Id. at 2040

[17] Id. at 2046

[18] Id. at 2043

[19] Riley v. California, 134 S.Ct. 2473, 2479 (2014)

[20] Id. at 2480

[21] Id. at 2481

[22] Id.

[23] Id. at 2486

[24] Id. 2488-89

[25] Id. at 2494-2495

[26] Id. at 2495

[27] Id.

[28] Riley, 134 S.Ct. at 2479

[29] Smith, 99 S.Ct. at 2581

[30] Id.

[31] Kyllo, 121 S.Ct. at 2045

[32] Riley, 134 S.Ct. at 2490

[33] Id. at 2495


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