Jenkins died of trauma to the head, caused by a fight he had gotten into the night before, police Sgt. Bill Hanley said in a news release.

Jenkins was sent to Patton, which houses severely mentally ill people referred by the criminal courts, in 1976 after being found not guilty by reason of insanity in connection with a schoolhouse arson fire in San Diego, his mother Felicia McCarty said.

Police and hospital officials declined to provide further information about Nall or the fight.

The violence comes as state mental hospitals, particularly Patton, face heightened scrutiny.

Federal prosecutors investigating civil rights violations filed a consent decree in federal court in May that called for sweeping reforms under a court-appointed monitor.

Federal investigators also released specific findings about Patton State Hospital, stressing among other problems high rates of patient-on-patient violence.

Last year, there were two homicides at Patton among patients, the first since 1994. Another patient committed suicide in January, the facility’s third since 2003.