How do we keep babies from growing into killers?

This was the headline on an opinion piece in the paper today. I glanced at the article. It appears to be well reasoned discourse on crazy people. I didn't read the whole thing, I'm full up on well reasoned discourse. What I want to do it react to the headline. Are you sure that's what you want? If babies didn't grow up to be killers, where would you get your killers from? I mean there are times when you want someone killed. That's part of the job description for soldiers and policemen, not to mention hitmen. And government contractors.
    Of course, what we want is someone who will only kill those people who "we" decide need killing, and only when "we" want it done.
    There is also the problem of what makes a suitable killer. Some people go all to pieces when they get involved in a violent confrontation. Some of them never recover. It doesn't phase other people. A few develop a taste for it. Reynald de Chatillon in Kingdom of Heaven said "I know what I am". No one actually came out and said just what he was, but I think he meant that he was a killer.