Supernatural - Jus In Bello Season 3 Episode 12

Sam and Dean break into Bela's apartment to find the Colt, but Agent Henricksen is on the scene and arrests them both on the spot. While Sam and Dean are locked up in a jail in Colorado, a demon breaks in, kills the police, and possesses Henricksen. After the brothers do away with the demon, the FBI release release them, only to learn from Ruby that the jailhouse is surrounded by demons who want Sam dead.