Supreme Court says geofence warrants need warrant

The Supreme Court ruled Monday that law enforcement must obtain a warrant to access an individual's historical cellphone location data, declaring that such digital dragnets constitute a search protected by the Fourth Amendment. The 6-3 decision curbs the use of "geofence warrants," a tool that allows police to compel technology companies to identify all devices present in a defined area at a specific time.

The ruling came in the case of Okello Chatrie, who was convicted of robbing a credit union in Midlothian, Virginia, in May 2019. After surveillance footage showed the robber using a cell phone, investigators, lacking other leads, obtained a warrant directing Google to provide anonymized location data for all devices within a 150-meter radius of the bank around the time of the crime. Through a multi-step process, police narrowed the initial list of 19 devices down to three, ultimately identifying Chatrie. His data showed him entering the area shortly before the robbery and leaving soon after. A subsequent search of residences linked to him recovered a gun, demand notes, and nearly $100,000 of the stolen cash. Chatrie pleaded guilty but reserved the right to appeal the use of...