It is hard not to wonder what goes through the mind of a serial killer. Something has to lead to their fascination of suffering and death.
Studies show that there is a definite cycle of abuse that starts with animals and leads to humans.
Serial killers often display fantasies that usually start when they are children. These fantasies can include cruelty to animals, abuse of other children, destructive play, a disregard for others, fire setting, theft and property destruction. The child fantasizing of control may dream of dominating the family dog, eventually going so far as to kick it. Finding kicking the dog rewarding, the future killer expands his behavior to beating, and eventually killing the dog. Aggressive fantasies that lead to killing are displayed by Patrick Sherrill, who killed 14 coworkers at a post office and then shot himself, had a history of stealing local pets and allowing his own dog to attack and mutilate them.