He was an outcast

He knew, too, that he would not stop at that. He finally understood that this was where things had been leading all his life. From the first moment that he had gone to school and mixed with the other children, he realised that he was different. He was an outcast. And so it had gone on, form the pain of trying to establish his first relationships with girls to the frustration he felt in married life and his growing attraction to his own students at school.

Now, at the age of 45, he realised what it all meant. He was like a drug addict who started with cannabis and ended up on heroin. At first, it was enough to look and to touch. But as time went on, he needed to hurt and destroy. Some sex offenders have a particular fetish - maybe for a kind of garment or a certain hair color.

Chikatilo's requirements were simpler. He needed suffering. He wanted to see the pain of his victims, to hear them cry out in agony. That was how he got his kicks. He did not rape in the ordinary sense. Knowing that failure was almost pre-ordained, he often made no attempt to have intercourse. Instead, he merely masturbated over their bodies. As if desperately trying to convince himself of his own adequacy, he tried to push his sperm into them with his hands. His satisfaction, however, came from the thrust of his knife and the blows from his fist. It was no coincidence, either, that he chose to kill in the woods. Here, of all places, he felt secure and at home.

~ (pg 55)