In a 6-3 decision in Chatrie v. United States,[1] the United States Supreme Court found that police officers conducted a search under the Fourth Amendment when they acquired location data from a tech company. In reaching its conclusion, the Court held that an individual has a reasonable expectation of privacy in records about his cell phone’s location, and police intrude on that constitutionally protected interest when they demand the information from a third-party company.
Background
Law enforcement officers sometimes use geofence warrants to obtain information that technology companies collect about their users’ cell phones located in the vicinity of a crime scene at around the time the crime was committed. If investigators know a crime was committed at a particular place and time, but do not have a suspect, they may draw a “geofence”—a virtual perimeter—around the crime scene and get a warrant compelling a company to hand over data about the cell phones located in that area near the time of the crime. Following a process specified in the warrant, the company will turn over the cell-phone data and eventually identify by name one or more of the users thus disclosed.
In May 2019, a man with a firearm robbed a credit union in Midlothian, Virginia. Local police officers learned, from witness interviews and surveillance-camera footage, that the robber had approached the credit union from a corner of an adjacent church, while appearing to talk on a cell phone. Officers could not find anything more.
In June, the officers applied to a Virginia magistrate for a geofence warrant directed to Google to obtain information regarding data from cell phones located within a 150-meter radius of the credit union for a period of time around the time of the crime. The application described the cell-phone location data Google collects through a service called “Location History,” which records the location of a user’s cell phone every two minutes or so with a timestamp. The signals tracked for Location History can determine a cell phone’s location within 20 meters. They can also ascertain a phone’s elevation, and thus reveal which floor within a building the phone is on. The application explained how that cell-phone location data could help identify the robber, possible accomplices, or additional witnesses. Success was particularly likely here, the application stated, because the robber appeared to be using his phone when he entered the credit union, and may even have been speaking with an accomplice. The officers’ proposed geofence was a circle with a radius of 150 meters surrounding the credit union.
The warrant described a three-step process that the police would follow: at step one, Google would produce anonymized location data for all cell phones within the geofence 30 minutes before to 30 minutes after the robbery; at step two, officers would attempt to narrow the list, and Google would provide additional anonymized data for that narrowed list, consisting of cell-phone locations both inside and outside the geofence during a two-hour period surrounding the robbery; and at step three, officers would further narrow the list, and Google would turn over identifying information, including names and phone numbers, for users on the final list. The magistrate issued the warrant, and through this process, Google ultimately produced three cell-phone users’ identifying information, including Okello Chatrie, whose location data showed that he entered the geofence about ten minutes before the robbery and headed toward a residential area immediately after leaving the bank.
After additional police work, a federal grand jury charged Chatrie with robbery and related firearms offenses. He moved to suppress the information the police obtained from Google, arguing that the officers had acquired that data through a Fourth Amendment search, and the warrant ostensibly authorizing that search was invalid. The District Court found that the geofence warrant violated Chatrie’s Fourth Amendment rights but denied the motion based on the good-faith exception to the exclusionary rule. A divided panel of the Fourth Circuit affirmed on different reasoning, holding that no search occurred because Chatrie “did not have a reasonable expectation of privacy in two hours’ worth of Location History data voluntarily exposed to Google.”[2] The Fourth Circuit granted rehearing en banc and affirmed in a one-sentence per curiam, with the court dividing evenly on whether a Fourth Amendment search had occurred. The United States Supreme Court granted certiorari solely on the question whether the police violated the Fourth Amendment in obtaining Chatrie’s location data.
Discussion
The Supreme Court explained initially that the Fourth Amendment protects “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” The “basic purpose” of that Amendment is “to safeguard the privacy and security of individuals against arbitrary invasions by governmental officials.” Carpenter v. United States, 585 U. S. 296, 303 (2018) (quoting Camara v. Municipal Court of City and County of San Francisco, 387 U. S. 523, 528 (1967)).[3] The Fourth Amendment “protect[s] certain expectations of privacy.” Soldal v. Cook County, 506 U. S. 56, 64 (1992). “When an individual seeks to preserve something as private and his expectation of privacy is one that society is prepared to recognize as reasonable,” then governmental “intrusion into that private sphere generally qualifies as a search.” Carpenter, 585 U. S., at 304. The Court stressed that the Amendment was designed “to place obstacles in the way of a too permeating police surveillance.” United States v. Di Re, 332 U. S. 581, 595 (1948). “[I]nnovations in surveillance tools” have “enhanced the Government’s capacity to encroach upon areas normally guarded from inquisitive eyes.” Carpenter, 585 U. S., at 305. The Court, in response, has sought to “assure[ ] preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.” Kyllo v. United States, 533 U. S. 27, 34 (2001).
In Carpenter, the Supreme Court held that accessing a form of cell-phone location information called cell-site location information (“CSLI”) is a Fourth Amendment search given individuals’ reasonable expectations of privacy. CSLI, is a time-stamped record generated each time a cell phone connects to a cell site which identifies an individual’s approximate location every time his phone makes a connection. The Carpenter Court explained that CSLI can provide a full “record of the holder’s whereabouts” and, with that, “an intimate window into a person’s life.” Ibid. People “compulsively carry” their cell phones “all the time.” Ibid. A cell phone thus “tracks nearly exactly the movements of its owner.” Ibid. The “newfound tracking capacity” that CSLI gives the police “runs against everyone”—not just those “under investigation”—and “travel[s] back in time.” Id. at 312. The Carpenter Court thus concluded: “[W]hen the Government accessed CSLI from the wireless carriers…it invaded Carpenter’s reasonable expectation of privacy in the whole of his physical movements.” Id. at 312-313.
Here, the Supreme Court found that the “resemblances between CSLI and Location History, in their relationship to personal privacy” were clear. The Court explained that “[e]verything Carpenter relied on to find that law enforcement officers conducted a Fourth Amendment search when they accessed wireless carriers’ CSLI records applies as well or better to the police’saccessing of Google’s Location History data.” First, Location History provides an even more fine-tuned picture of a person’s movements than CSLI, pinpointing location within around twenty meters rather than within sectors of one-eighth to four square miles; Location History records location every two minutes or so for a daily average of 720 chartings rather than 101; and Location History can estimate elevation to reveal which floor of a building a phone is on. Second, Location History allows police to reconstruct “retrospective[ly],” and with no real effort, people’s comings and goings in any area, enabling “tireless and absolute surveillance” of any number of people in any number of places, public and private. Carpenter, 585 U. S. at 312. Third, Location History implicates personal privacy interests even more than CSLI, because Location History is more the cell-phone user’s own. Most cell-phone users have no awareness of CSLI records, and would never try to retrieve them; by contrast, Google users regularly employ Location History as effectively a personal journal. In this way, Location History resembles other private materials—e.g., emails, documents, photographs, or calendars—that even if stored on Google’s servers, a user reasonably views as his own and expects to be shielded from the “inquisitive eyes” of the government. Id. at 305.
The Court observed that the Government’s main argument was that accessing only a short amount of cell-phone location information (whether Location History or CSLI) does not count as a Fourth Amendment search. The Government maintained that a person has no reasonable expectation of privacy in two hours’ worth of Location History data as was acquired by police here because for this amount of time, the person’s movements would reveal little about the details of their personal life. The Court disagreed, explaining that “even short-term monitoring” of a person’s physical movements can provide “a wealth of detail about [his] familial, political, professional, religious, and sexual associations.”[4] More fundamentally, the Supreme Court stated that it had “never understood Fourth Amendment protections as being applicable only once an intrusion ‘goes too far.’”[5] “Where the Fourth Amendment applies, it applies—regardless of ‘the quality or quantity of information’ the government obtains.” See Kyllo, 533 U. S., at 37. The Court added that what creates the Fourth Amendment concern about “a too permeating police surveillance” (Di Re, 332 U. S., at 595) is that the government can access all of a cell-phone user’s movements, in both public and private places; the sweep of the official invasion is not made less because the government, with the benefit of hindsight, can pinpoint exactly which few hours of movements it wants to review.
The Government also contended that the third-party doctrine precluded Chatrie from invoking the Fourth Amendment’s protections. The Government claimed that in authorizing Google to collect, retain, and use his location information, Chatrie lost his legitimate expectation of privacy, and therefore his right to complain of a search. However, Carpenter refused to apply the third-party doctrine to CSLI. The Supreme Court here found that both differentiating features highlighted in Carpenter applied equally or better to Location History for the previously discussed reasons: Location History is even more revealing of an individual’s movements than CSLI, and the information is “not truly shared,” in the normal sense of wanting a third party to see or use it. Carpenter, 585 U. S. at 315. The exposure of that information to Google is just what happens when a user avails himself of one of the services on his cell phone.
The Government argued that generating Location History, unlike producing CSLI, is a voluntary choice on the user’s part. Although carrying a cell phone may be indispensable in modern society, the Government argues, using Location History is not. However, the Court found that argument ignored how and why Google users turn on Location History: Google repeatedly prompts users to turn on the service, often warning that devices will not work correctly otherwise, while not disclosing in that prompt how frequently users’ location information would be recorded, how precise it would be, or how that minute-by-minute location information might be given to the government. A more fundamental problem was that the Government’s proposed app-by-app, feature-by-feature method of granting Fourth Amendment protection misapprehended the nature of modern cell-phone use, where nearly everything requires some kind of “affirmative act” beyond “powering up” a given app or service. In the Court’s view, the Government’s position would mean a distinction between the activities people do on their cell phones from the mere act of carrying a turned-on cell phone (the thing that generates CSLI), with only the latter receiving assured Fourth Amendment protection. However, the Court observed that the point of carrying smartphones is to use what is on them to use the apps and “services they provide.” Carpenter, 585 U. S. at 315. Accordingly, a cell-phone user is not to be viewed as sharing private information with third parties—which then can be freely passed on to the government—just by doing the ordinary things cell-phone users do. The Court thus held that police officers invade a cell-phone user’s reasonable expectation of privacy when they access his Location History, and concluded that when the government accesses historical cell phone location information—Location History as much as CSLI—it conducts a search under the Fourth Amendment.
The Court explained that its conclusion did not resolve this case, however, because the Fourth Amendment prohibits only unreasonable searches. Because the Fourth Circuit panel concluded that no search had occurred, it did not address whether the geofence warrant issued here validly authorized each stage of the search process. Nor did the en banc court’s per curiam opinion speak to that issue. Noting that the Supreme Court is a court of review, not of first view, the Court left it to the Court of Appeals to decide whether, at each step of the search process, the warrant satisfied the Fourth Amendment’s requirements of particularity and probable cause. Accordingly, the Supreme Court vacated the judgment of the Fourth Circuit and remanded the case for further consideration on those issues.
Justice Alito, joined in parts by Justices Thomas and Barrett, dissented. The dissent argued that both Carpenter and the majority opinion in the instant case were “giving criminal suspects a protected Fourth Amendment interest in any sensitive personal information about them that is collected and owned by third parties.” The dissent warned that the majority’s decision would “send seismic waves through our Fourth Amendment doctrine.” The dissent maintained (as did Justice Barrett in her short separate dissent) that Chatrie had no reasonable expectation of privacy in data about his public movements that he voluntarily disclosed to Google. The dissent maintained that the Court should not have granted certiorari in the first place, but having done so, the Court should have either dismissed the case or affirmed the lower court’s decision based on the “good faith” exception to the exclusionary rule. Because the full 4th Circuit had held that Chatrie could not overcome that exception, and the Supreme Court declined to weigh in on that issue, its ruling would have no real impact. The dissent maintained that on the merits, under traditional search-and-seizure principles, Chatrie could not challenge the geofence procedure here under the Fourth Amendment.
HOW THIS AFFECTS YOUR AGENCY
Agencies may note that the majority stressed that it did not address whether the good-faith exception to the exclusionary rule still allowed the admission of the Location History data in this case, and left that question for the Fourth Circuit to consider.
According to the dissent, Google, the Government, and the majority all agreed that Google has modified its Location History service in a manner that forecloses future use of the geofence procedure that was used by police in the case here. (See the December 2023 article here announcing the change:https://blog.google/products-and-platforms/products/maps/updates-to-location-history-and-new-controls-coming-soon-to-maps/; and a current description here: https://support.google.com/maps/answer/6258979 stating: “When Timeline is on, even when Google apps aren’t in use, your precise device location is regularly saved to your device. You also have the option to store an encrypted backup of your Timeline to Google’s servers in case you change devices.” (Italics added.) It is unclear if this means that Google can no longer access said data should police seek such information from Google.
As always, if you wish to discuss this matter in greater detail, please feel free to contact James Touchstone at (714) 446–1400 or via email at jrt@jones-mayer.com
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[1] 2026 U.S. LEXIS 2878 (June 29, 2026).
[2] 107 F. 4th 319, 325.
[3] We discussed the Carpenter decision in Client Alert Vol. 33, No. 17, available at https://jones-mayer.com.
[4] United States v. Jones, 565 U. S. 400, 415 (2012) (opinion of Sotomayor, J.).
[5] See Pennsylvania Coal Co. v. Mahon, 260 U. S. 393, 415 (1922).