Arm of the police department

TASER

This non-lethal device delivers an electric shock to temporarily incapacitate a suspect, often used from a distance for safety. It’s named after a famous inventor’s early 20th-century fiction.

"Arm of the police department" plays on the double meaning of arm—it can refer to a branch of an organization or a literal weapon. Here, it hints at the TASER, a handheld device police use to subdue suspects with electric shocks. The wordplay cleverly ties the idea of an arm (like a limb or tool) to a piece of law enforcement equipment. It’s a straightforward but clever misdirection common in crosswords.