SANTA ANA, Calif. (AP) — A California university professor who was arrested on arson charges wrote in an email that he was thinking of getting a dozen machine guns and shooting at least 200 students at his late son’s high school, according to court papers obtained Wednesday.

UC Irvine pharmaceutical sciences professor Rainer Reinscheid was upset after his teenage son hanged himself in an Irvine park in March after the boy had been disciplined by the assistant principal at University High School, prosecutors said.