I think people are getting too stressed. 13 year old kids commit suicide because they get stressed out at school. If i got really really stressed i'd go crazy. Losing your house in an earthquake would be pretty stressful. And depression, theres another reason for people going crazy. Then again, crazy people arn't always the people who commit crimes.
Back to the original question, if there is another massacre i dont think it'll be directed at one specific race. Lets just hope it doesn't even happen.