Flatbush Det. Joe Keough thinks the latest rape-strangulation credited to a serial killer the press has dubbed The Lover is really the work of someone else -- and he's right. But Keough's already got a reputation as a hard case among colleagues who put team play and a high arrest rate above getting the right guy. Then shortly after he compares notes with Det. Len Swann, the sharply observant clerical on the Lover Task Force, Swann gets killed in his home -- the victim, Keough's convinced, of stop-at-nothing Lt. Dan Slovecky, the Task Force head, who's hot to claim every killing that fits the Lover's profile so that he'll be guaranteed a fat promotion when the Task Force brings him in. When a tense scene between Keough and Slovecky erupts in violence, it looks like Keough's washed up in the department -- until the patrician Lover, stung by the suggestion that he committed the copycat crimes (underage victims who were killed in Brooklyn, for crying out loud), decides to thumb his nose at the Task Force by playing ball with Keough. Weird. The behavior of both killers defies belief, but veteran Randisi's workaday authority in handling the boys in blue puts this miles above his fumbling recent novels about shamus Miles Jacoby (Stand-Up, 1994, etc.).