Dragnet (1967)

S4E3 S.I.U. - The Ring

Joe and Bill are on duty in the Special Investigation Unit when their informant, known as "Black 10," requests a meeting with them. During their discussion, Black 10 reveals information about a bartender who is selling a stolen jade ring. Taking this lead, Joe and Bill orchestrate a sting operation aimed at retrieving the ring along with any other stolen jewelry in the bartender's possession.