HE created comic books with ghastly drawings of people shooting each other and wrote stories about zombies.

Authorities were today trying to determine what caused a teenager to gun down his grandfather, put on the man’s police-issue belt and bullet-proof vest, and drive his marked squad car to a high school, where he began shooting his classmates at will.

A neo-Nazi teenager who called himself the Angel of Death killed his grandfather and then stole his weapons and police car before embarking on a bloody shooting spree at a United States school, it emerged tonight.

The teenager who went on a shooting rampage on a remote US Indian reservation yesterday, killing his grandparents at their home and then seven people at his school, was a neo-Nazi.