Horrible, what happened at Virgina Tech. Can you imagine one moment a ‘normal’ person entering a hall and shooting at every human at sight? And that in cold-bloodedness, it’d seem. No, it can’t be a normal person. But the sad thing about it is perhaps we’d never know why he did this. He shot himself dead too, typical of mass killers.
That reminds me of one such incident last year here in Mauritius. One guy killed his three brothers in a row, and a neighbor who tried to rescue them. Then he walked up and down the main road before finally triggering the bullet beneath his chin, which burst his head. Passersby stood stunned. We came to know later that his younger brother whom he killed at second sight had had an argument with the killer’s child and his wife. The killer and all the persons killed were fasting at that moment.
The psychology of mass murder is still to be explored. Lots of books have been written, and lots of research done into the brain system that controls emotions and behavior. No clue found yet as to what really triggers such behavior. Studies tend to suggest that mass killers appear externally normal, but internally disturbed, angry, depressed, humiliated. They may also be experiencing romantic failure or sexual apprehensions. They enter into a phase of no-return in the fit of rage and when they realize what they’ve done they don’t know how to get out of it; they don’t want to be caught. The next step is suicidal.
You may wish to read further on this here