an unusual gunman

In this morning's Washington Post, there was an article about an unusual gunman that, if it were fiction, no one would believe. Check it out. The consensus seems to be that something miraculous happened. What makes someone turn to violence? Can we reach the human being inside the animal that is perpetrating a violent crime? At what point is the mode of violence so out-of-control within a person that they can't be reached anymore? This article raises some interesting questions. What happened? Could it just be "love"?