There are people who are born to kill. Met a few. No conditioning required. But if you take them out of the equation your point is sound for the other ninety nine percent.
I looked after a guy who as a teen with no dodgy background whatsoever, left his sisters bed room window open so he could climb in from the outside at night and make it look like an intruder.
He was fifteen at that time, and from England, so it was a shock in little old NZ in the early 80's when the cops realized this polite toffee speaking Pommy kid staged his sisters Murder.
So why did he do it? He said in an interview that he liked his sister, he just wanted to know what it felt like to kill someone and she was at hand next door, and that he was aware no one would look at the fifteen year old sibling.
This guy was in his forties when I met him, if he were in the prison system he would have long been released, decades earlier.
But because he was grabbed by Psyche they never wanted him on the streets again.
Which is interesting when you consider how your average Joe thinks that a killer under a mental health banner is there to fake madness and get an early release.....