The punitive consequences for this type of behavior results in life imprisonment or the death penalty. Did you have some harsher than that in mind? I think the punishment is very harsh but it doesn't stop these types of predators so it's important to figure out how they come to be. I'm certainly not trying to justify a savage, rapist murders actions. There are all sorts of motivations to murder. Someone who kills a rival gang member is a different type of killer than one who viciously beats, rapes and kills a stranger or multiple strangers. If the why's can be uncovered maybe someday we can figure out ways to prevent someone growing into a monster like this. It's not excusing what he did. It's trying to understand why so it can be prevented.
Lots of things in life have "been around since the beginning" it doesn't stop scientists and doctors from trying to understand them so we can progress and be better, do better. By all means though, you feel free to tell all the law enforcement, social workers,profilers, therapist, teachers, psychologist etc who dedicate their lives to attempting to understand how killers operate so they can prevent these types of crimes how useless it all is.