Fourth Circuit rules cellphone-tower mimicry requires a warrant

In a decision issued Thursday, a Fourth Circuit panel declared that deploying a cell-site simulator to obtain a suspect’s real-time location is a search under the Fourth Amendment and therefore requires a warrant. The case involved Kerron Andrews, who was arrested in Baltimore after police used a court order to employ the simulator and locate him inside a townhouse. Judges Nicole Berner and Toby Heytens, both appointed by President Biden, emphasized that the technology allows the government to peer inside a private residence, a practice the Supreme Court has consistently required a warrant for.

The judges did not resolve whether the pen-register order previously obtained by the police met the warrant standard, but they affirmed that the officers are protected by qualified immunity, leading to the dismissal of Andrews’ civil action. Judge A. Marvin Quattlebaum Jr. concurred, noting the panel should have first addressed the constitutional violation claim. The underlying criminal case was dropped after a Maryland court ruled a warrant was needed for the simulator use. The decision marks the first appellate ruling that real-time cellphone tracking with such devices is a search.