A Greenville man was arrested after posing as a law enforcement officer and accidentally pulling over a deputy in an unmarked vehicle, according to Nola.com.

The Louisiana media source reports that William Gilchrist, 45, was in Kenner when he allegedly activated the flashing blue and white lights and siren he’d illegally installed in his vehicle and attempted to pull over a detective with the Jefferson Parish Sheriff’s Office who was driving south on the Airport Access Road in Kenner.

Gilchrist was arrested late Wednesday on charges of impersonating an officer, possession of fraudulent identification and improper lighting, Sgt. Brandon Veal told reporters.

Authorities said the detective initially thought he was legally being pulled over, but then realized the driver wasn’t actually legitimate law enforcement. When Gilchrist pulled away, the detective pulled in behind him turned on his lights, to which Gilchrist responded by turning his blue and white lights back on.

Nola.com reports that the detective saw he had a “State Police Fugitive Task Force” tag holder. When Gilchrist was pulled over, he allegedly handed the detective a badge and an ID card that appeared to be from the U.S. Marshals Service.

Gilchrist has been booked into the Jefferson Parish Correctional Center in Gretna.