A US professor set fires at his son's high school and a school administrator's home after the boy committed suicide.
Rainer Reinscheid, a University of California, Irvine professor, has pleaded guilty to six counts of arson, three counts of attempted arson and resisting or obstructing an officer.
On Tuesday he apologised for his actions and said he had lost himself in grief, as he pleaded with the judge for a lenient sentence.
Reinscheid's 14-year-old son hanged himself last year after he was disciplined by a school administrator for allegedly stealing from the school store. Reinscheid's private emails described a graphic plan to attack the boy's school.
The hearing will continue on Wednesday afternoon local time.
* Contact Lifeline on 13 11 14 or Kids Helpline 1800 55 1800 (for young people aged 5 to 25) for information about suicide prevention
