There is a LOT going on in this book. If you don't like complicated, run. I have even seen references to this book as 'Literature'. This is the story of a cop, hunting a serial killer with victims who are not what they appear to be. However, it's not really about that at all. It's complicated.
None of the victims exist. They have social security numbers that don't match their names, no family, no friends, no previous addresses. I am not sure how much of this story is factual, but if it is, it's highly disturbing.