A Simple Act of Violence, R. J. Ellory

Washington, embroiled in the mid-term elections, did not want to hear about serial killings. But when the newspapers reported a fourth murder, when they gave the killer a name and details of his horrendous crimes, there were few people that could ignore it. Detective Robert Miller is assigned to the case, and rapidly uncover a complication. The victims do not officially exist. Their personal details do not register on any known systems. And as Miller unearths ever more disturbing facts, he starts to face truths so far-removed from his own reality that he begins to fear for his life. Winner of the Theakston's Crime Novel of the Year award.