A Mississippi homeowner caught a would-be catalytic converter thief and held him at gunpoint until police arrived.

Harrison County Sheriff’s Office deputies said they received a call early Monday from a resident. The homeowner told investigators he heard the noise of what he thought was a saw and grabbed a pistol to investigate.

He found John Thomas Cearley, 50, of Long Beach, Mississippi, under the homeowner’s car.

Cearley was allegedly trying to cut the catalytic converter from under the exhaust system of the man’s car, investigators said.

Cearley was charged with possession of burglary tools and possession of a controlled substance.

A catalytic converter is part of a vehicle’s exhaust system.