NEWPORT BEACH, Calif. (AP) — A university professor who wrote emails outlining a plan to attack the California high school that his late son attended before committing suicide wrote an additional email that described his attempts to burn the school and the assistant principal's home.

The Orange County Register reports (http://bit.ly/QVkLv4) the email was written about a week before University of California, Irvine professor Rainer Reinscheid was arrested on suspicion of setting fires at the school, the home of the assistant principal who disciplined his son and the park where the teen's body was found.

Prosecutors previously filed with the court three emails that they say detail Reinscheid's plans for a mass murder at University High in revenge for his son's death.

Defense attorney Ron Cordova and prosecutor Andrew Katz didn't return calls seeking comment.