Dragnet.

LAPD Sgt. Joe Friday -- the equally straight-laced nephew of the famous police sergeant of the same name -- is paired up with a young, freewheeling detective named Pep Streebeck. After investigating some strange robberies at the local zoo and the theft of a stockpile of pornographic magazines, they uncover cult activity in the heart of the city and are hot on the case to figure out who's behind it all.