Real Life Serial Killers which book/movie interests you

I am sorry about such a morbid topic, but over the past year I have gotten friendly and close to the man who defended John Wayne Gacy, the Hon. Sam Amirante (Ret). I read his book Defending a Monster and it was quite interesting. I am not trying to name drop or advertise the book (which will soon be a movie, , I just use this to qualify why I am interested in what others here think and what real life "monster" interests them).

Gacy truly was something else. I had seen several movies about him, read several books before meeting Sam, but none were from the "inside" perspective. It was definitely different than anything else on the "man" (and I use the term loosely to describe Gacy).

Anyway, so who "interests" you and why?

Gacy interested me because he was like Stephan King's IT, being the clown who terrorizes and kills. He took 2 common fears, the "perfect neighbor" and the "clown" and combined them. It is also scary that a man with his previous arrest records got so close as to have his picture taken with the First Lady at the time (Roselyn Carter).

 

Ed Gein.
When I was a kid in Wisconsin he was always talked about as a boogeyman serial killer who made lampshades and furniture from human body parts. When I looked into it (read what he actually did) I found that he only killed two people and most of his body part arts and crafts came from grave robbing, not murdering hundreds. What's surprising is how he was the inspiration for fictional serial killers (Psycho, Leatherface, etc.) who had much higher body counts.

 

Jeffrey Dahmer.
Dahmer murdered 17 men and boys between 1978 and 1991, with the majority of the murders occurring between 1987 and 1991. His murders involved rape, dismemberment, necrophilia, and cannibalism.
It's not so much interest in what he did, cause lets face it, thats pretty disgusting. It's more of wanting to know what happens to a person that makes them do such things. What could have happened in his life that would lead him down such a path?