Book similar to story I made up in my mind where a normal person is moulded to be an assassin or killer.

I had an idea for a story where there’s an organization or something like that that scouts out people in daily life who might exhibit sociopathic or psychopathic tendencies. They give them a scenario where they are given a chance to murder and are observed. Those who pass that test are then coerced (somehow) into learning how to become a professional killer.

Doesn’t have to be that specific but you get my drift.