Reid takes this without batting an eyelash. He's a good listener, attentive, and he doesn't discredit what he's told-- but he isn't bothered by it, either.

"There's extensive theoretical debates about that very question," he answers. "You can think of it as the classic nature versus nurture argument, although it's more refined and nuanced within the realm of violent crime psychology. Our best guess right now is that the end result is due to both. Maybe someone has a predisposition, but--" Spencer slows, for once, tone growing quieter. "We always look for catalysts. People don't do things for no reason. Under the right conditions, I've also killed people."