Baretta: Can't Win for Losin'... (1976)

Synopsis
Sanford and Son regular Whitman Mayo guest stars as John Rich, a ghetto father whose son is "on the junk." Witnessing the murder of the dope pusher who hooked his son, John takes credit for the killing, thereby becoming a neighborhood hero. He also becomes the next target of the pusher's real killers, obliging undercover cop Tony Baretta (Robert Blake) to come to the rescue. ~ Hal Erickson, All Movie Guide