The Maze Of Blood and Bones

My name is John Mallory. I am a police investigator. I have been with the Police firm for twenty years. I've been on the investigation of a killer who we have given the nickname of "Z," because of how he kills his victims... He knocks them out then binds their arms and legs and he then slashes their throats into a "Z" pattern with his doctor's scalpel. After doing all of this he hangs them up to display like pieces of art with large butcher hooks.