Showing Act of Love by Joe R. Lansdale

Homicides in Houston's Fifth Ward tend to be fairly mundane: domestic violence, gang-related shootings, that sort of thing. None of it forgivable, but all of it understandable. Crimes of passion, crimes of pride, crimes of poor impulse control. But suddenly there's something new in the Ward at night... a sickness with human form. Someone who dissects and eviscerates and takes trophies. Someone with wet, unknowable urges to satisfy. Someone who leaves mocking notes, taunting the police for their powerlessness. Detectives Hanson and Clark are on the case, but leads are thin on the ground. It's almost as if the killer's among them, listening, anticipating, concealing... and increasingly, terrifyingly, he's making it personal.