A 2019 armed robbery near Richmond, Virginia, is pushing the so-called "geofence warrant" to the U.S. Supreme Court. The case may reshape how police use the vast amounts of location data held by technology platforms to target suspects. That year, a gunman snatched $195,000 from the vault of Call Federal Credit Union before the police arrived. Traditional investigation methods stalled after obtaining surveillance video and interviewing witnesses. A detective applied for a geofencing order from Google, requiring the company to provide the location data of all devices that appeared near the bank within about an hour before and after the crime.
Following this data clue, the police finally identified Okello T. Chatrie, 31, and mapped out his complete whereabouts based on his Google "location history", which became one of the key pieces of evidence for the conviction.
The focus of the current dispute in the Supreme Court is not whether the police can use such data - in the Chatrie case, the government did apply for and obtain a search warrant - but whether this kind of search method based on geofencing, first demarcating the area and then screening the equipment, meets the Fourth Amendment's requirements for "reasonable search" and "specificity." Today, when mobile phones continue to send location data to services such as Google Maps, the amount of information involved in such searches far exceeds the traditional concept of "single suspect records."
Chatrie's attorney, Adam G. Unikowsky, argued in written submissions and court arguments that a geofencing warrant is essentially similar to a "broadcast search warrant" that the Fourth Amendment to the U.S. Constitution seeks to prohibit because it allows the government to "first conduct a broad search and then develop suspicion." He emphasized that personal location history is private data stored in password-protected accounts, and that users handing over this information to Google does not mean they agree to hand it over to the police.
At the court hearing, several justices asked questions that broke down the usual ideological divides. Neil Gorsuch and Sonia Sotomayor asked government lawyers whether the same legal logic used to defend geofencing orders could also open the door to large-scale access to emails, photos or documents in the cloud. Samuel Alito and Brett Kavanaugh were more concerned about the impact of the ruling on police case handling practices. Kavanaugh asked the defense to explain why the steps taken by the detectives on the Google platform in this case were considered "bad police work." Instead, he believed that this operation "deserves recognition."
Lawyers from the U.S. Attorney General's Office, representing the U.S. Department of Justice, argued that Chatrie's voluntary sharing of location data with Google was no different from the public handing over financial records to banks or call records to phone companies. They also noted that surveillance video showed Chatrie carrying and using his cell phone during the robbery as part of a consensual act.
Chief Justice John Roberts showed some sympathy for both sides during questioning. In a confrontation with the defense lawyer, he once said that users can avoid risks by turning off the tracking function - "If you don't want the government to obtain your location history, just turn it off, what's the problem?" But he then asked the government: If the police can use this mechanism to target all visitors to a specific church or a specific political organization within a certain period of time, will it evolve into a systemic threat to civil liberties.
On a technical level, this case relies on the “location history” architecture once used by Google. Under this design, as long as the user chooses to turn it on, the service will collect coordinates every two minutes and store long-term trajectories in the cloud, thus providing the possibility for geofencing orders: the police first delineate a virtual boundary and time interval on the map, and Google will search the database accordingly, first give an anonymous device number, and then gradually disclose more specific device information after multiple rounds of "circling reduction."
Lower courts have been divided on this type of search. In Chatrie's first trial, a federal judge found that the geofencing order violated the Fourth Amendment's requirements of reasonable suspicion and specificity, but still allowed the relevant evidence to be used in the trial based on the "good faith exception" principle, arguing that the officer involved acted reasonably in reliance on the existing legal framework at the time. Subsequently, a panel of the Fourth Circuit Court of Appeals upheld the search results on different grounds, holding that Chatrie did not have a "reasonable expectation of privacy" in the two-hour location history he shared with Google. The full court review deadlocked 7 to 7, and his conviction was upheld.
The last time the Supreme Court explicitly addressed the issue of cell phone location data was in 2018 in Carpenter v. United States. The court ruled at the time that police generally needed a search warrant to obtain historical cell site location records, sending an important signal that the fact that the data was held by a third-party company was not enough to deprive it of its constitutionally protected status. Courts have since set tighter limits on police's use of GPS tracking and searches of personal phones without a warrant.
During oral arguments on Monday, several justices suggested that using geofences to access location history likely should fall under the "warrant search" side of the Carpenter decision, and that it was the court's responsibility to clarify the scope and boundaries of the relevant search warrants. At the same time, the technical environment surrounding geofencing data is also evolving rapidly: Google said it stopped responding to geofencing orders last year as it adjusted its storage model and moved location records from centralized servers back to users' local devices, claiming that it no longer had the same aggregated location database that could be "caught in one go" in the past.
But even if Google withdraws, law enforcement agencies have not given up similar tools, but have turned their attention to other large technology companies. The report pointed out that police have begun making similar requests to platforms such as Apple, Lyft, Snapchat, Uber, Microsoft and Yahoo, while continuing to rely on data tools such as automatic license plate recognition systems and artificial intelligence-driven family genealogy comparisons in major cases. Any nationwide rule on geofencing mandates, once issued by the Supreme Court, will almost certainly spill over to other location-aware applications and cloud services, affecting the real-world "visibility" of future citizens carrying their phones every day.