I Am Not a Serial Killer by Dan Wells
I recently read, actually no, devoured Dan Wells' I Am Not a Serial Killer about teenager John Wayne Cleaver. John is a clinically deemed "sociopath" and has always been fascinated by things most people consider wrong, namely serial killers. Of course, it doesn't help that his family owns the local mortuary.
In I Am Not a Serial Killer, the first of a trilogy, John battles many things. Among them are his therapist, his mother, a set of rules to avoid becoming a serial killer and now a heightened interest in a new serial killer that just happens to live in his town.
If you are looking for a good horror with a touch of mystery, this is definitely the book for you. And don't forget to check out the sequel Mr. Monster and the thrilling conclusion, I Don't Want to Kill You.