The entire team is on the take, mostly from drug dealers. The Feds begin a corruption investigation into the unit. Williams is "turned" by a team of Federal attorneys (Norman Parker, Paul Roebling, James Tolkan, Steve Inwood). Williams tries to protect himself and his team from the inquiry, but eventually is obligated to testify in court against his fellow cops to save himself.
The increasingly neurotic Williams becomes a marked man, and is defended by a rotating team of Federal gunmen. Williams' marriage to Lindsay Crouse becomes strained but survives. It becomes apparent that Williams has engaged in many more shakedowns than he has confessed to, and has committed multiple counts of perjury by not revealing those payoffs in court testimony.
How others will see it. This lengthy and unhappy movie drew attention upon release, mostly due to the heralded reputation of director and co-writer Sidney Lumet. At the Golden Globes, the movie picked up prestigious nominations for Best Picture, Best Director, and Best Actor (Williams), but the Oscars only nominated the screenplay. Despite those festival nods, the film was a box office disappointment.
Today at imdb.com, the movie has a humble total of 6K user votes. The user ratings are high at 7.6 out of 10 with little demographic spread. The most helpful user reviews are unfailingly positive ("possibly the best cop film ever made") but negative reviews lurk deeper down this list, complaining about the film's lengthy and repetition, the galaxy of nefarious Italians to keep track of, and Williams' over-the-top jittery behavior.
How I felt about it. Sidney Lumet's cinematic directorial career began on a high note: 12 Angry Men. It bogged down by the early 1970s, and was rejuvenized by Serpico (1973). That film was about a passionate and honest cop who was so despised by his fellow bribe-taking cops that they set him up to be murdered. The present movie is different, in that Williams is a dirty cop. Otherwise, the two films cover about the same ground, except that Williams is no substitute for Al Pacino, and screenwriter Jay Presson Allen is no Waldo Salt.
If Treat Williams is not believable here, it is because he is all over the map. The Three Faces of Treat are cocky, angry, and mopey. It is impossible to feel sorry for a man who accepts tens of thousands of dollars in payoffs (in mid-1960s dollars), and later commits many acts of perjury, and thinks he should escape prison through undercover work. He doesn't even pay restitution for the money he took from criminals, and he presumably retires with a policeman's pension.
There are three classes of people in this movie: criminals, cops, and Feds. But the cops are criminals with a badge. It is the Feds who are different. They are better educated, from upper middle class WASP families, and see themselves as superior to the corrupt cops who ostensibly are on the same side of the law. Their arrogance shows as they move the cops around like chess pieces on a prosecutorial chessboard, deciding which ones are captured and which ones remain in the game.