This is going to sound bitter, but after all the pain he caused, he only spent ten years in prison. As far as law enforcement can tell, his crimes started in 1975 (after raping a young girl in Germany). He spent 35 years as a free man- he became a husband, a father, and then a grandfather. He celebrated holidays, went on vacations, watched his children grow up, and enjoyed the simple daily joys of being a human being. He didn’t go to jail until he was 57 years old.
Additionally, all of the details of his crimes died with him. There could still be dozens of families out there who will never know what happened to their loved ones.