Lies from Beyond by Vincent Valentean
When psychic medium Michael Merlyn was run out of the small town of Westfield Texas, he thought that nothing would ever make him return. But when an old friend is found murdered, Michael is forced to return to his hometown and use his special gift to commune with the dead to track down a vicious serial killer targeting ordained priests. Can Michael unravel the clues left for him by the spirits of the dead and save a town that hates him? Or will he fail and leave his former home to the whims of a demented maniac?