It's good that this violent spree has ended. But déjà vu--what's the motive? Once again experts on the workings of human behavior will weigh in to shed light on what makes some people nutty enough to do such horrible things. Once again we will learn that a perfect storm of environmental factors and personality traits combined to bring about these abnormal happenings. And once again, such enlightenment on the matter will seem inadequate to prevent a recurrence of similar events in the future. Why? Because there are untold numbers of people who also have this perfect storm of ingredients who will not be the next individual to commit horrific acts. Behavioral scientists still lack the tools for predicting which solitary individual will become the next person to have a "why?" next to their name. I have read about scientists who have spent their careers trying to comprehend serial killers, and have come to the conclusion that some people are just plain evil, which is not very scientific. I personally think we will remain in the dark concerning many human behavioral problems until we learn a great deal more about the human brain, which many scientists are working hard at doing this very moment.