Based on a true story about Cannibal Albert Fish, this movie hits ya. It gives quite a few realistic gory details without showing what they can't, and makes you realize how disturbing Fish really was.The real Albert Fish
It digs deep into his childhood, explaining a little bits of reason for his disturbance. He was paddled alot as a child, resulting in his excitement for future paddling with a board covered in nails. He became a child rapist and cannibal, as you can see here.