SANTA ANA, Calif. (AP) — A professor who pleaded guilty to setting fires and whose private emails described a graphic plan to attack his late son's high school is a brilliant scientist and doting father who was despondent over the boy's suicide, his supporters said Thursday.

Rainer Reinscheid, a pharmaceutical sciences professor at University of California, Irvine, appeared in court in OrangeCounty, but a judge delayed sentencing to take more time to review the extensive paperwork in the case.

About two dozen people attended the hearing for Reinscheid, who is now set to be sentenced Aug. 20 on six counts of arson, three counts of attempted arson and resisting or obstructing an officer. He could face between three and 18 years in prison.

Reinscheid's brother and two friends — who will be unable to attend the next hearing — told the court they couldn't imagine that the German-born scientist whose research helped produce breakthroughs in the treatment of pain would commit the crimes.

"Ever since Claas took his life, Dr. Reinscheid was extremely sad," Wei Si, a graduate student who studied under Reinscheid, said about the professor's son. "He looked 10 years older overnight."

Prosecutors want the maximum sentence for Reinscheid, who set fires at UniversityHigh School in Irvine, a school administrator's house and the park where his 14-year-old son hanged himself after being disciplined for allegedly stealing at the school.

Authorities say emails were seized from Reinscheid's account outlining a plan to attack the campus, commit sexual assaults and burn down the school before killing himself. No charges were filed related to those emails.

"It's absolutely tragic what happened to his son, but that in no way justifies the serial arson vendetta he began against these people, these institutions that were absolutely blameless and had nothing whatsoever to do with the death of his child," said Andrew Katz, a deputy district attorney for Orange County.

Reinscheid had previously faced a potential maximum sentence of more than 21 years in state prison but pleaded guilty last month in a deal with Judge Gregg L. Prickett.

Reinscheid, a faculty member at UC Irvine for about 13 years, was arrested last year after police found the emails describing the plan to buy machine guns and attack the school.

Defense attorney Joshua Glotzer said Reinscheid was not in his right mind after his son's death.

"Any action is an aberration," he said.