A university professor is being held after emails allegedly revealed he was plotting mass murder at his late son's school.
Rainer Reinscheid, 48, an associate professor at the University of California, Irvine , plotted to kill students and administrators at the school where his son studied before killing himself, police say.
His son killed himself last Spring following a disciplinary hearing over a theft in the student shop at University High School.
The professor had been granted bail over a number of alleged arson offences at the school but was re-arrested after prosecutors said they had found disturbing new email evidence.
The emails allegedly reveal a plot by Reinscheid to kill students and administrators at the high school, where his son was disciplined before his death.
After Reinscheid's arrest last week, authorities said they found emails on his mobile describing a plot to burn down the school.
The emails also allegedly detail sexual assaults and plans by Reinscheid to buy weapons and murder school officials and students before killing himself.
"I can only at this point tell you, he laid out in sufficient detail plans to purchase guns and murder lots of people," deputy district attorney Andrew Katz said in an interview.
At the latest hearing, the judge denied Reinscheid bail and postponed his arraignment until next week - he had previously been on bail before the discovery of the emails.
Authorities said Reinscheid is believed to have set five fires and tried to set another, using newspapers, fireplace logs, a book and other items to ignite them.
According to UC Irvine's website, Reinscheid's research included studying molecular pharmacology and psychiatric disorders, including studies of schizophrenia, stress, emotional behavior and sleep.
If convicted, he faces up to 13 years in prison.