When we turn on the news and see headlines describing the deeds of a serial killer, we immediately wonder “How could a human being do something like that?” and “What drove him over the edge?” When trying to unravel these mysteries, investigators often look to the person’s past. They search for an event or series of events that led this seemingly normal person to their ultimate fall from the realm of the socially acceptable into the world of the criminally insane. But then, we wonder if there is more at work behind these actions than a traumatic childhood or series of bad experiences. Was this person born broken? Are they evil? Most researchers accept that the deviant behavior of serial killers is a combination of many factors. When questioned about nature vs. nurture, one psychologist asked, “Which contributes more to the area of a rectangle, its length or its width?” And yet, there is no simple answer, and some maintain that the circumstances into which a person is born determines their personality.