Key Witness

No sooner has corporate litigator Wyatt Matthews won the biggest lawsuit of his career than he suffers a spasm of middle-aged idealism and volunteers to spend six months in the public defender's office. His first client is a teenage black stickup artist accused of being the ''Alley Slasher,'' a rapist and serial killer. As he confronts a mountain of circumstantial evidence and a cunning jailhouse snitch, Matthews must also contend with his society wife's outrage over his involvement with the case. Despite the ingenious plot, Key Witness won't win any writing prizes; the dialogue often reads like a poor translation from an unknown foreign language. Still, J.F. Freedman exhibits the kind of raw storytelling power that keeps readers turning pages deep into the night. B