The Unmasker

The goriest, coolest and most stylish killer ever, only known as The Unmasker, is called in by the cops of Amentia(the diemension from my novel The Black Cross). But...not for the things that he has done. The cops realize the only way to understand a psychopath is to call in another psychopath. Sure they have done it in TV shows. But having a killer constantly killing the most important people of the country, you would have to call the only person that can understand him inside out. So the questions should be: how well does The Unmasker understand a doppelgänger? Can the authorities trust The Unmasker? And will each of them keep to the deal?