The fourth feature (1995) by this country’s most gifted black filmmaker, Charles Burnett (Killer of Sheep), is his first with a directly political edgea heartfelt and persuasive look at the racism and corruption of the Los Angeles police force, based on a true story and calculated to burn its hard lessons straight into your skull. The plot concerns the adjustments made by a sincere black rookie cop (Michael Boatman) who joins an all-white precinct and wants to be accepted by his fellow officers; his only real ally turns out to be the one woman in the precinct (Lori Petty, in a singular performance), a Jew who gets plenty of abuse herself. When a murder case arises involving a black suspect (Ice Cube), the hero’s decision to perjure himself in order to support his white partner opens a Pandora’s box of ironies and ambiguities that the movie squarely faces. The distributor forced him to tone down the anger and despair of his original ending, but this still packs a mighty punch. With Elliott Gould and M. Emmet Walsh. 108 min. (JR)