A person with a mental illness can do lots of things, but that should not deny them the treatment they need.
If he was mentally ill,when was he denied treatment?
As far as I am concerned,he crossed the river of no return when he shot the 9 year old girl in the back of the head. That,in my opinion, puts him in the pure unadultred evil category. There are millions of mentally ill individuals that do not murder children.