Supreme Court Signals Support for Geofence Warrants in Chatrie Case

The Supreme Court heard oral arguments in Chatrie v. United States this morning, with justices appearing inclined to uphold law enforcement's use of geofence warrants to collect location data from cellphone users near crime scenes. Chief Justice Roberts presided over the session, which began at 10:05 a.m. and addressed a practice that has become increasingly central to digital-age criminal investigations.

The case centers on Okello Chatrie, who was convicted of armed robbery after law enforcement used a geofence warrant to identify his cellphone as one of a handful of devices near the Call Federal Credit Union in Midlothian, Virginia, during a May 2019 robbery. Police subsequently obtained a traditional search warrant for Chatrie's home based on this location data, leading to evidence that secured his conviction.

Fourth Circuit's Reasoning Under Review

The case reached the Supreme Court on certiorari from the Fourth Circuit, where a divided panel affirmed the district court's denial of Chatrie's motion to suppress the evidence. The Fourth Circuit held that the geofence warrant did not constitute a Fourth Amendment search because Chatrie lacked a reasonable expectation of privacy when he voluntarily provided Google with his Location History data.

This reasoning directly conflicts with a federal appeals court ruling in New Orleans, which found geofence warrants to be general warrants categorically prohibited by the Fourth Amendment. The circuit split created the constitutional question now before the Supreme Court.

Adam Unikowsky, representing Chatrie, argued that geofence warrants violate the Fourth Amendment's particularity requirements. However, the justices did not appear to embrace arguments that these warrants are too general to comply with constitutional standards.

Technical Mechanics of Geofence Surveillance

Geofence warrants compel technology companies—primarily Google—to provide location data for all devices within a specified geographic boundary during a defined time period. Law enforcement typically uses a three-step process: first obtaining anonymized location data within the target area, then requesting additional information on devices of interest, and finally seeking subscriber information to identify specific individuals.

This technique differs fundamentally from traditional cell tower data requests, which target known suspects. Geofence warrants cast a digital dragnet, collecting location information on all users within the perimeter before investigators know who committed the crime.

The practice has grown substantially since its introduction around 2016. Court filings indicate that Google received more than 11,000 geofence requests from U.S. law enforcement in the first half of 2020 alone, representing a significant portion of the company's total law enforcement data requests.

Amicus Brief Alignment

The case drew substantial attention from civil liberties organizations and government entities. The ACLU, ACLU of Virginia, Electronic Frontier Foundation, and Georgetown Law's Center on Privacy & Technology filed an amicus brief supporting Chatrie's position. Additional privacy advocates including the Brennan Center, Center for Democracy and Technology, Surveillance Technology Oversight Project, and Defending Rights & Dissent submitted their own brief challenging the practice.

On the other side, the Local Government Legal Center and International Municipal Lawyers Association (IMLA) filed amicus briefs supporting the government, arguing that geofence warrants provide essential investigative tools for local law enforcement agencies.

Historical Context and Precedent

We have seen this pattern before, when the Court grappled with digital surveillance in Carpenter v. United States. In that 2018 decision, the Court divided 5-4 in favor of a defendant whose movements were tracked through cellphone tower data for nearly four months without a warrant. The Carpenter decision established that prolonged location tracking constitutes a Fourth Amendment search requiring a warrant, but left open questions about shorter-term location requests and the voluntary sharing of data with third parties.

The Chatrie case tests the boundaries of Carpenter's protection. Unlike the extended surveillance in Carpenter, geofence warrants typically cover brief time periods around specific criminal events. The voluntary disclosure question also carries different weight, as users may not understand that enabling Location History makes their movement data accessible to law enforcement through geofence requests.

Looking at the trajectory from traditional physical searches to cell tower data to geofence warrants, each technological step has forced courts to reconsider Fourth Amendment applications. The current case represents another iteration of this ongoing evolution, with potential implications extending beyond location data to other forms of bulk digital collection.

Implications for Digital Privacy Framework

The Court's apparent inclination to support geofence warrants would establish significant precedent for digital-age surveillance. A ruling in the government's favor could validate law enforcement's use of similar location-based investigative techniques, potentially extending to other forms of bulk data collection from technology platforms.

For technology companies, the decision affects their legal obligations and the scope of their cooperation with law enforcement requests. Google and other platforms have already implemented procedural changes to limit the scope of geofence data, but a Supreme Court validation of the practice could influence their broader data retention and sharing policies.

The ruling will also shape how lower courts evaluate emerging surveillance technologies. As law enforcement agencies increasingly rely on digital investigative tools—from facial recognition systems to automated license plate readers—the constitutional framework established in Chatrie will influence the evaluation of these techniques under Fourth Amendment standards.

A decision is expected by the end of the Court's current term in June.