Chatrie, Location Data, and the Slow Death of Discretion: How Digital Surveillance is Outpacing the Fourth Amendment

By Bryan Gomez '27

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Introduction: The Legal Race to Rein in Novel Technologies

Long before geofence warrants entered the national conversation, the Supreme Court had already begun grappling with how the Fourth Amendment applies to the digital tools that now mediate nearly every aspect of daily life. In Riley v. California, decided June 25th, 2014, the Court held that police generally need a warrant to search the contents of a cell phone seized during an arrest, reasoning that cell phones are “such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy.” (1) As humankind and our technology advance in an ever-accelerating march into the future, the law has endeavored to match this cadence by applying and adapting centuries-old jurisprudence to the issues brought on by human progress; the digital era is no exception. Since Riley, the Court has engaged in a delicate balancing act, attempting to thread the needle between empowering law enforcement with the necessary tools to conduct investigations and protecting the public from an unprecedentedly intrusive class of searches and seizures enabled by technologies our Founding Fathers could never have foreseen. The issue of geofence warrants is one such circumstance.

A geofence is a virtual perimeter drawn around a physical location, typically defined by GPS coordinates or a radius from a central point. A geofence warrant directs a technology company, most often Google, to disclose location data for every device within that perimeter during a specified window of time, allowing law enforcement to cast an extraordinarily wide net to identify potential suspects. (2) Google is the primary recipient of these warrants because it widely uses the location data it collects, including through its Location History service, to provide enhanced user experiences across its application ecosystem. (3) Everything from local restaurant recommendations when using Google search to suggested routes when navigating via Google Maps to weather alerts relies on this data. While users voluntarily opt into the use of this service, Google frequently warns users that opting out may disrupt service or, in some cases, make the application altogether inoperable. (4) Because this data was, until recently, stored in internal databases such as Google's SensorVault, the government could access the location data of large swaths of users and retroactively pinpoint the location of suspects with a level of precision never before seen. (5)

Due to the far-reaching impact of this investigative technique, countless cases have arisen challenging the government's use of geofence warrants, necessitating national guidance by the Supreme Court. (6) The case that ultimately forced the Court's hand arose from a 2019 bank robbery in Midlothian, Virginia. With no suspect identified, the Chesterfield County Police Department sought a geofence warrant covering the area around the crime, and the resulting search eventually led investigators to Okello Chatrie. (7) His challenge to that search is the subject of this piece.

Carpenter's Connection to Chatrie

To understand how the Court arrived at its decision in Chatrie, it is essential to look back to the holding in Carpenter v. United States, which limited the government's ability to conduct warrantless searches of cell data. (8) In Carpenter, the Supreme Court weighed whether the warrantless acquisition of cell-site location information (CSLI), or geolocation data generated by cell towers when cell phones make and end calls, constitutes an unlawful search under the Fourth Amendment. The Court held in favor of the defendant, protecting his reasonable expectation of privacy in his CSLI. (9)

The central question in Chatrie was whether Google's Location History data is or is not akin to CSLI. The petitioner argued that the frequency, precision, and widespread use of Location History gave users a reasonable expectation of privacy, given the sensitive nature of much of the information collected. The government, by contrast, argued that users' voluntary submission to the collection of this data forfeited that expectation, appealing to the third-party doctrine, a legal principle holding that individuals forfeit their expectation of privacy when they voluntarily provide information to a third party, such as a telephone company (10) or a bank. (11) The government further argued that, although a user cannot use Google's applications without generating Location History, the same is not true of using a cell phone itself; because turning on Location History requires an affirmative choice distinct from simply carrying a phone, the government's position was that users were truly volunteering this data to Google.

However, for a multitude of reasons, including the prolific use of this service in almost all facets of modern life, its uniquely invasive nature, and the lack of notice to users of potential government requisitions, the Court found that despite users' decision to opt into the service, examining Location History data does constitute a Fourth Amendment search, therefore requiring a warrant. (12)

The Fourth Amendment's Particularity Requirement for Warrants

The Fourth Amendment's particularity requirement exists to prevent exactly the kind of indiscriminate search and seizure once permitted under general warrants, an English legal instrument that allowed officers to investigate a suspected crime without limitation. (13) Geofence warrants put that requirement to the test because of how they operate in practice, as the three-step process used in Chatrie illustrates.

Following the 2019 bank robbery, a Virginia magistrate signed the geofence warrant, and police identified 19 individuals within the 150-meter geofence during a window spanning 30 minutes before and after the crime. (14) From there, police applied a series of filters across two additional steps, ultimately narrowing the list to three individuals. Google's reluctance to hand over identifying information for the full 19 was what forced this phased narrowing in the first place; one of the three, Okello Chatrie, was the defendant. (15)

While the majority declined to rule on whether these additional steps were constitutional, Justice Jackson took particular issue with the significant latitude afforded to law enforcement by the warrant's language regarding the narrowing done in Steps 2 and 3. The warrant states that the Chesterfield County Police Department would “attempt to narrow down the list” without, as Justice Jackson notes, setting forth any criteria or guardrails for this process. (16) Were it not for Google's reluctance to hand over identifying information, police would have had free rein to collect the names, dates of birth, phone numbers, and precise location data of the nearly twenty individuals swept up in the initial geofence, plus the unconstrained movements of nine individuals during the two-hour second step. Barring the existence of a large conspiracy to rob this credit union, the geofence warrant in Chatrie invaded the privacy of more than a dozen individuals with no connection to the crime. Extrapolated across the more than 20,000 geofence warrants Google alone received between 2018 and 2020, millions of Americans have been unknowingly searched not for crimes they were suspected of committing, but for the simple fact of having been near one. (17)

The Significance of Chatrie and its Future Implications

With all of this in mind, the significance of the Court's ruling is clear: the government conducts a Fourth Amendment search when it acquires Location History, as it did here. (18) It would be a mistake, however, to read this as the end of geofence warrants altogether. The Court clarified that Location History is a constitutionally protected class of information requiring a warrant to search or seize, but it did not prohibit geofence warrants outright, and it was careful not to specify what would make one constitutionally sufficient. (19) That is where the warrant's particularity, not merely its existence, becomes the operative question.

Consider, by contrast, a hypothetical warrant seeking Location History data limited strictly to the interior of a single store during the ten minutes surrounding a shoplifting incident, where the warrant itself specifies that officers may only pursue identifying information for a device matching a physical description already captured on the store's security footage. Unlike the open-ended instruction to merely “attempt to narrow” the list employed in Chatrie's warrant, this hypothetical warrant builds its own particularity into its text, cabining both the area searched and the criteria for narrowing the pool of suspects before a magistrate ever signs off. The distinction is not whether a geofence warrant sweeps in bystanders; virtually all of them do at the outset. It is whether the warrant itself constrains how and on what basis officers may narrow that initial pool. Chatrie's warrant left that discretion almost entirely undefined. One way the Fourth Circuit could resolve the particularity question on remand is by requiring exactly this kind of ex ante specificity: criteria for narrowing the pool built into the warrant itself, rather than left to officers' discretion after the fact.

The matter of the second and third steps' lack of judicial oversight remains otherwise unreviewed, and lower courts will have to work out how the particularity requirement applies to warrants like Chatrie's that leave officers free to widen the area, individuals investigated, and time frame of a search. (20) That question may outlive its original context: Google's 2025 shift to on-device, encrypted Location History storage has already closed off the specific pipeline this case concerned, even as the underlying constitutional question persists. (21)

Despite these open questions, the Supreme Court's ruling in Chatrie was squarely in line with its duty to uphold the Fourth Amendment. At a time when skepticism of the judicial branch is at a seeming all-time high, the Court shielded the sacrosanct principle of privacy in an age when it is imperiled by an endless onslaught of technology, guided in no small part by Google's own advocacy for stronger protections around the data it collects. (22) But the deeper work is unfinished. Chatrie established that acquiring Location History is a Fourth Amendment search; it did not establish what makes a geofence warrant particular enough to satisfy that Amendment. That question, remanded in substantial part to the Fourth Circuit, is the one that will determine whether Chatrie meaningfully constrains the next generation of geofence warrants, or merely renames the same invasion of privacy the Fourth Amendment was written to eliminate.

Endnotes

1. Riley v. California, 573 U.S. 373, 385 (2014).

2. Clay Wild and Peter Berris, "Geofence Warrants and the Fourth Amendment," Congressional Research Service, Legal Sidebar, January 22, 2026, https://www.congress.gov/crs-product/LSB11274.

3. Google, "How does Google use location information?," Google Privacy & Terms, accessed July 2026, https://policies.google.com/technologies/location-data?hl=en-US.

4. Ibid.

5. Jennifer Valentino-DeVries, "Tracking Phones, Google Is a Dragnet for the Police," New York Times, April 13, 2019.

6. Amy Howe, "Supreme Court Takes Up Four New Cases, Including Disputes on Geofence Warrants and Roundup Weedkiller," SCOTUSblog, January 16, 2026, https://www.scotusblog.com/2026/01/supreme-court-takes-up-four-new-cases-including-disputes-on-geofence-warrants-and-roundup-weedkiller/.

7. Chatrie v. United States, No. 25-112, slip op. at 6 (U.S. June 29, 2026).

8. Carpenter v. United States, 585 U.S. 296 (2018).

9. Ibid.

10. Smith v. Maryland, 442 U.S. 735 (1979).

11. United States v. Miller, 425 U.S. 435 (1976).

12. Chatrie, No. 25-112, slip op. at 2.

13. William J. Cuddihy, The Fourth Amendment: Origins and Original Meaning 602–1791 (Oxford University Press, 2009), 21.

14. Chatrie, No. 25-112, slip op. at 8.

15. Ibid.; see also Ibid., slip op. at 2 (Jackson, J., concurring) (explaining that officers narrowed the list "only because Google insisted on it").

16. Chatrie, No. 25-112, slip op. at 1–2 (Jackson, J., concurring).

17. Zack Whittaker, "Google Says Geofence Warrants Make Up One-Quarter of All US Demands," TechCrunch, August 19, 2021, https://techcrunch.com/2021/08/19/google-geofence-warrants/.

18. Chatrie, No. 25-112, slip op. at 29.

19. Chatrie, No. 25-112, slip op. at 29–32; see also "Chatrie v. United States," Knight First Amendment Institute at Columbia University, accessed July 2026, https://knightcolumbia.org/cases/chatrie-v-united-states.

20. Chatrie, No. 25-112, slip op. at 32; see also National Association of Criminal Defense Lawyers, Fourth Amendment Center, "Practice Advisory: Chatrie v. United States — What Defense Counsel Need to Know," June 2026, https://www.nacdl.org/Content/United-States-v-Chatrie,-No-3-19-cr-130-(E-D-Va-).

21. Chatrie, No. 25-112, slip op. at 4, n. 2; see also Andrew Crocker and Jennifer Lynch, "Victory! Supreme Court Says Constitution Protects People's Location Data," Electronic Frontier Foundation, June 29, 2026, https://www.eff.org/deeplinks/2026/06/victory-supreme-court-says-constitution-protects-peoples-location-data.

22. Jessica Lyons, "Should Google Location Data Be a Tool for Cops?," The Register, February 2, 2023, https://www.theregister.com/on-prem/2023/02/02/should-google-location-data-be-a-law-enforcement-tool/687546.