I am looking for a 90s-2000s documentary about teenagers who murdered their parents or relatives. One of the murderers is a teenager with schizophrenia, who murdered his grandparents. He heard voices in his head saying that he should kill his grandfather and grandmother. First he wanted to commit a suicide and drove around the neighborhood, where he was arrested for speeding, but the police let him go. Then he came to his home and murdered his grandparents with a knife or with an ax. The documentary also shows his portrait, a fat boy wearing eyeglasses.
(Not “Teen Killers: a Second Chance?” (1998), “Why did Johnny Kill?” (1988))