A police crime thriller focuses on crime stories from a law enforcement perspective. Examples include The Untouchables, Out of Time, and Scarface. Seven (1995) follows two detectives hunting a serial killer targeting victims for the seven deadly sins. Gangster Squad (1949) depicts cops battling a ruthless mobster running Los Angeles. The Departed (2006) involves an undercover officer and police mole infiltrating the Irish mafia in Boston, often ending in bloodshed as loyalties are tested. Key conventions include the use of guns, alcohol, tough protagonists, and portraying law enforcement in an imperfect light.