And the stress of modern life may cause an increase in violent tendencies.

The urban environment is the incubator for all sorts of undesirable behaviors.

However much his atrocities disgust us, he may actually consider himself a hero.

This is common among those who, in the popular slang, "go postal".

In his tortured mind, he may feel he was battling against impossible odds.

It is not unusual for such individuals to believe the entire fate of the world rests with them.

In the end, our subject has displayed all the classic symptoms of paranoid delusions.

We may never know exactly what set him off, but rest assured, we have plenty of time to study him.