Rehabilitation is about identity-restoration. It is about replacing self-destructive behavior that has superficial roots in one's identity with self-constructive behavior that has deep roots in one's identity. In drinking to excess, one is not being true to oneself; and rehabilitation replaces such behavior with behavior that is true to oneself. But in killing, a natural born killer is being true to himself; so the concept of rehabilitation does not apply. Thus, setting aside people who kill in self-defense or under otherwise singular and extreme circumstances, people kill because they are killers--because it is who they are. And the concept of rehabilitation therefore does not apply.