the thing with criminals or anyone for that matter, is they don't do this kinda shit for absoloutely no reason. A normal person with normal parents and a happy childhood doesn't end up being a serial killer or a child rapist. Chances are they have fucked up genes from fucked up parents, chemical imbalances, fucked up childhoods, fucked up lives, fucked up everything. I know it's hard to have sympathy for a guy like Couey and the like, and the initial reaction is to say fuck em and kill em but the truth is he's had a fucked up life needs lots and lots of help.
But at his age and for his crime he probably can't be cured, so the best solution for him would probably be to put him out of his misery and give him the death sentence.