Laughing Policeman (1973) Rating: Starring: Walter Matthau, Bruce Dern, Louis Gossett Jr., Albert Paulsen, Anthony Zerbe Director: Stuart Rosenberg Category: Drama, Thriller Studio: 20th Century Subtitles: English, Spanish Length: 109 mins.     It's tough beat for San Francisco police lieutenant Jake Martin (Walter Matthau) when he has to investigate a city bus massacre in which a madman opened machine gunfire on eight people. It's even worse when Martin discovers his former partner, Detective Dave Evans, is one of the victims. But as he investigates the grisly murders, Martin not only discovers unsavory things about Evans, but he finds that many of the victims had shady lives, which shrouds the killer's identity even more. Also starring Louis Gossett Jr. and Bruce Dern, The Laughing Policeman is filled with plot twists, suspense and fascinating fun.