The Streets of San Francisco - Season 4 - Eps 20: Clown of Death
Two retired brothers, both having worked as riggers for circuses many years before, are found murdered while a circus happens to be performing in San Francisco at the Cow Palace.
About The Streets of San Francisco

Title: The Streets of San Francisco
First Air Date: 1972-09-23
Last Air Date: 1977-06-09
Status: Ended
Rating: 6.945/10 (from 91 votes)
Language: EN
Seasons: 6
Total Episodes: 119
Network: ABC
Genres: Crime, Drama, Action & Adventure
Production Companies: Quinn Martin Productions (QM), Warner Bros. Television
Synopsis
Two police officers, the older Lt. Stone and the young upstart Inspector Keller, investigate murders and other serious crimes in San Francisco. Stone would become a second father to Keller as he learned the rigors and procedures of detective work.
Cast

Karl Malden
Mike Stone

Michael Douglas
Steve Keller

Richard Hatch
Dan Robbins