A frustratingly not-terrible action thriller.
"The Laughing Policeman" is an awfully good police movie: taut, off-key, filled with laconic performances. It provides the special delight we get from gradually unraveling a complicated case. It's almost the kind of movie, indeed, to blast loose a detective-novel fan from Ross Macdonald.
Instead of depending on sex and violence for its appeal (although it does contain them), it fascinates us with the way a criminal is finally tracked down. The movie opens with a virtuoso cat-and-mouse scene in which an off-duty policeman trails a criminal, who apparently, for some reason, wants to be tailed. They get on the same bus together and then a stranger in the back of the bus opens fire with a machine gun and kills everybody aboard. He escapes.
The story begins when Walter Matthau, as a detective, arrives at the scene and identifies the dead cop as his partner. But . . . the partner was supposedly home on sick leave. What was he doing on the bus?
The challenge is to check out the backgrounds of everybody else on the bus in order to track down the killer. And here the movie gets interesting; the police work has the feeling of authenticity. We get the false leads, the dead ends, the plea-coppers, the impossible coincidences, and the nuts who are ready to confess to the crime. And all the time, as Matthau explains, there's the feeling that the case will never be cracked unless somebody just comes in and squeals.