The Fourth Amendment Follows Your Phone: Supreme Court Clarifies Limits on Geofence Warrants

The Fourth Amendment Follows Your Phone: Supreme Court Clarifies Limits on Geofence Warrants

What Happened in the Case?

In Chatrie v. United States, local police investigating a credit union robbery in Virginia obtained a geofence warrant directing Google to produce Location History data for devices located within a 150-meter-radius, a geofence, of the credit union during the hour surrounding the robbery. Google first produced anonymized location data, and officers later narrowed the results and obtained identifying information for three users, including Okello Chatrie. Chatrie moved to suppress the Google location data, arguing that the warrant violated the Fourth Amendment.

What Is a Geofence Warrant?

A geofence warrant is a court order directing a technology company, like Google, to produce location data for cellphones or devices reflected in the company’s location records as being located within a defined geographic area during a specific time window. Law enforcement agencies use geofence warrants when investigating crimes where the suspect is unknown but was likely present at a particular location. For example, following a bank robbery or a hit-and-run, an agency might seek data on devices near the scene at the relevant time in order to identify potential suspects.

The process typically proceeds in stages: the agency first receives anonymized location data for devices responsive to the geofence, then narrows the list to devices of interest, and finally requests identifying information for those specific devices.

The Court's Decision

On June 29, 2026, the Supreme Court held that law enforcement’s acquisition of Google Location History data through a geofence warrant constitutes a search under the Fourth Amendment. Justice Elena Kagan delivered the opinion of the Court and held that individuals retain a reasonable expectation of privacy in their cellphone location data even when that information is held by a third-party technology company. The Court rejected the argument that sharing location data with a service provider eliminates any Fourth Amendment protection.

The Court's analysis focused on the nature of the information at stake. Cellphone location data, the Court reasoned, can reveal an extraordinarily detailed picture of a person's movements, associations, and private life, even when collected for a short period of time. The Court also held that a user does not lose Fourth Amendment protection simply because the data is held by a third-party technology company. In other words, individuals retain a reasonable expectation of privacy in digital location data, even for short periods, and even though a third party holds that data in the cloud. Chatrie, 609 U.S. ___, slip op. at 29.

The Court did not categorically prohibit geofence warrants. Instead, the Court left for the Fourth Circuit to decide whether the specific warrant in this case satisfied the Fourth Amendment’s requirements of probable cause and particularity at each stage of the multi-step process. The case was vacated and remanded to the Fourth Circuit to determine whether the warrant at issue met those standards.

Why It Matters for Local Agencies

Local law enforcement agencies that use or are considering geofence warrants should be aware that requests for this type of location-history data are now clearly subject to Fourth Amendment scrutiny. Absent an applicable exception, warrant applications must be supported by probable cause and must describe the scope of the search with particularity.

As a practical matter, agencies should consider reviewing geofence and digital-location warrant templates, narrowing requests by time and geography where possible, documenting the investigative basis for each stage of the request, and coordinating with agency counsel before seeking geofence or similar reverse-location data.

For the full opinion, please see: https://www.supremecourt.gov/opinions/25pdf/25-112_0am4.pdf