Supreme Court Rules that a Geofence Warrant Is a Search

The Supreme Court decided several major cases in its recently-concluded Term, but for people interested in the Fourth Amendment, the most anticipated was United States v. Chatrie, __ U.S. __ (June 29, 2026), a case about so-called geofence warrants. We already knew, from Carpenter v. United States, 585 U.S. 296 (2018), that police conduct a search for Fourth Amendment purposes when they access days or months of cell site location information (CSLI) about a suspect from a cellular service provider. The central issue in Chatrie was whether police conduct also conduct a search when they access a few hours of location information about a cell phone user from a company that builds smartphone apps that collect such information.

Overview. Justice Kagan’s introduction lays out the heart of the case:

Through a geofence warrant, police officers required Google to turn over Location History data revealing cell phones within the vicinity of a bank at around the time it was robbed. At the end of the multi-step process described in the warrant, Google gave the police three names. The Federal Government soon charged one of the individuals thus identified, petitioner Okello Chatrie, with committing the crime. . . .

We decide . . . today . . . that the police conducted a search when they gained access to [Chatrie’s] Location History data. 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—even though for only a limited time, and from a third-party tech company. We leave to the Court of Appeals the further question whether, given the warrant issued, the search here was reasonable, meaning that each of its steps was properly described with particularity and found to be supported by probable cause.The majority expressly declined to address the potential application of the good faith exception to the exclusionary rule, a point to which I will return below.

The decision was 6-3, with Chief Justice Roberts, Justice Sotomayor, Justice Kavanaugh, and Justice Jackson joining Justice Kagan’s opinion and Justice Gorsuch concurring in the judgment. Justice Jackson wrote a concurrence that Justice Sotomayor joined. Justice Alito wrote the lead dissent, joined in part by Justices Thomas and Barrett, and Justice Barrett wrote an additional dissent.

The majority opinion. Justice Kagan began with by explaining that cell phone apps track users’ location:

Your maps app wants to help you navigate from Point A (where you are) to Point B (where you are going). Ride-sharing apps of course track your location when you are using them, and often do so even when you are not. Weather apps want to tell you about local conditions. Fast-food apps want to identify the closest burger and pizza joints. Fitness apps want to track your running routes.

At the time the Chatrie case arose, Google apps asked users to activate a feature called Location History, which enabled Google to detect their location to within about 20 meters every two minutes. Hundreds of millions of users enabled Location History, allowing Google to create a massive database of users’ locations. Thousands of times per year, police used search warrants to access the database and obtain information about users who were in close proximity to the scene of a crime at the time the crime occurred.

Pertinent to this case, that’s exactly what happened after a Virginia credit union was robbed in May 2019. Police obtained a geofence warrant seeking information about phones that were within 150 meters of the credit union near the time of the robbery. In response, Google engaged in a back-and-forth process, generally described in the warrant, by which it provided progressively more information to police about progressively fewer users. Ultimately, it provided Okello Chatrie’s name and contact information to police along with about two hours of location data about him.

Chatrie was charged with the robbery. He moved to suppress the data obtained via the warrant, contending that the process was a search and that the warrant did not satisfy the Fourth Amendment’s probable cause and particularity requirements. The district court agreed with Chatrie’s Fourth Amendment analysis but determined that the police acted in good faith and so denied the motion to suppress. Chatrie pled guilty and appealed. A panel of the Fourth Circuit affirmed for a different reason, concluding that no search occurred because Chatrie had voluntarily shared his location with Google and therefore had no reasonable expectation of privacy in that information. The Fourth Circuit reheard the case en banc and affirmed per curiam with multiple judges writing opinions expressing widely divergent legal analyses. (You can read more about the Fourth Circuit’s proceedings in prior posts here, here, and here.)

For the Supreme Court majority, the case was a fairly straightforward application of Carpenter:

The resemblances between CSLI and Location History, in their relationship to personal privacy, practically leap off the page. Everything 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’s accessing of Google’s Location History data.

Specifically, the majority highlighted the fact that Location History is more precise than CSLI and is collected more frequently, making police access to the data more intrusive.

The Government sought to distinguish Carpenter on two principal grounds. First, it noted that the data collected in Carpenter covered a much longer time period than the two hours of data collected in Chatrie. The majority responded that even two hours of data may reveal deeply private activities. More fundamentally, “[w]here the Fourth Amendment applies, it applies,” and the majority saw no precedent for applying it only when police conduct “goes too far.”

Second, the Government acknowledged that Carpenter declined to apply the third-party doctrine to the CSLI at issue there but framed that decision as based on a lack of voluntariness: it is necessary to have a cell phone to participate in modern life, and it is necessary to convey CSLI to a provider to enable a phone to function. By contrast, the Government argued that sharing one’s location information with Google is not necessary. Most users choose not to share, and sharing requires an active opt-in, albeit one that Google vigorously promotes. Therefore, the Government contended, the third-party doctrine applies to Location History information and Chatrie had no reasonable expectation of privacy in such data.

The majority disagreed. It noted that Google’s opt-in requests fail to describe in detail the amount of information that Location History collects and that the opt-ins may go so far as to say that the user’s phone will not “work correctly” without enabling the feature, seemingly rendering any consent less than voluntary. The majority also criticized the idea that the number of users who opt in is a valid indicator of voluntariness, because some countries prohibit Google from asking users to share and because any rule based on participation rates invites impossible line drawing: what if 50% opt in? What if 75% do? Ultimately, the majority concluded that “[t]he point of carrying smartphones is to use what is on them,” so accepting the terms of service of various apps cannot amount to foregoing constitutional protections.

Having determined that accessing a user’s location data is a search, the majority left for the lower courts the question of whether the search here was a reasonable one supported by a valid warrant. The parties dispute, among other things, whether the procedure used in the warrant satisfied the Fourth Amendment’s particularity requirement, and whether the warrant allowed the police to play too large a role in narrowing the scope of the information requested.

The concurring opinions. The issues described in the preceding paragraph were the focus of Justice Jackson’s brief concurrence. She would have concluded that “this search violated the Fourth Amendment” because the multi-step process used to provide progressively more detailed information about progressively fewer individuals was not supervised by a judicial official and left too much discretion in the hands of Google and the police.

Justice Gorsuch concurred only in the judgment. He would not have relied on the reasonable expectation of privacy test adopted in Katz v. United States, 389 U.S. 347 (1967), which he views as hopelessly indeterminate and lacking any basis in the text of the Fourth Amendment. Rather, he would have held that a user’s location information is one of the “papers and effects” referenced in the Fourth Amendment. The information “amounted to an electronic diary or map of [Chatrie’s] travels,” even if held for him by Google, so when the police accessed it and reviewed it, they conducted a search.

The dissent. Justice Alito began by observing that “not one iota of the majority opinion will affect the outcome of this case,” because the evidence in question was obtained under a search warrant, and under United States v. Leon, 468 U. S. 897 (1984), the exclusionary rule does not apply to evidence obtained in good faith under a search warrant even if the warrant is later determined to be deficient. For that reason, he viewed the case as an advisory opinion that the Court should never have issued.

He further argued that the Court should not have granted review because “Google has modified its Location History service in a manner that forecloses future use of this geofence procedure.” Essentially, Google has stopped collecting users’ location history on its servers, and instead now leaves that information on users’ devices. Therefore, a search warrant for location information directed at Google will come up empty and the specific facts of Chatrie will not be repeated. In Justice Alito’s view, that makes this case a poor candidate for discretionary review.

Finally, Justice Alito turned to the merits of the Fourth Amendment question. First addressing the older, property-based understanding of the Fourth Amendment invoked by Justice Gorsuch, he reasoned that Chatrie had no property right in his physical location, so he could show no search of his “papers or effects.” Looking next at the Katz privacy-based understanding of the Fourth Amendment, he would have concluded that the third-party doctrine applies and defeats any expectation of privacy in the information at issue. He rejected the idea that this case is controlled by Carpenter, noting that the duration of information sought here was short; that the information centered on a credit union, a public place; and that the information was shared with Google via an affirmative opt-in process.

Justice Barrett wrote separately to say that she was satisfied with the Court’s decision to review the case, but would have ruled, for the reasons given by Justice Alito, that Chatrie had no reasonable expectation of privacy in the location information obtained here.

Discussion. Justice Alito is likely correct that the Court’s opinion will do nothing for Chatrie. The Leon good faith exception will almost certainly be deemed to apply. Nonetheless, Chatrie is an important decision because of its implications for law enforcement practices going forward.

Although Google has changed the way it handles location data, many other apps still collect users’ location information. For example, Starbucks describes its data collection practices in this Privacy Notice. The notice says that Starbucks apps and services collect both “general” and “precise” location information about users “for purposes . . . such as to provide you with information about stores near you, to enable you to remotely order and pay for our products and services, or so that you may have certain Starbucks products delivered to you by a third-party vendor.” The notice does not place any specific limit on how long Starbucks may keep your location information. While you can configure your device not to share that information, “some Starbucks Services may not work properly without information about your location.” Given all the data that Starbucks collects, it is not far-fetched to imagine law enforcement seeking user location information from Starbucks. Under Chatrie, such a process seems to be a search that normally will require a valid warrant.

But Chatrie raises as many questions as it answers. We still don’t know whether it is even possible to draft a valid geofence warrant, or whether the three-step progressive sharing procedure used by Google is a viable approach. More broadly, Chatrie may have implications for other types of search warrants that try to identify a suspect through a big database search, such as search warrants asking Google to disclose the identity of users who enter specific search terms. One might argue that the third-party doctrine applies to that type of data, but Chatrie casts serious doubt on the viability of the third-party doctrine as it pertains to digital information. Readers interested in pondering the larger issues implicated by Chatrie might check out this analysis from Tech Policy Press.