An autopsy Tuesday on a Camarillo State Hospital patient who was found dead in his bed after an attack by another patient failed to reveal any fatal injuries, the Ventura County coroner's office said.
Coroner's Investigator Dale Zentzis said the Monday morning incident at the psychiatric hospital will have to be investigated further to determine what caused the death of Mark W. Wagner, 37.
After Wagner died at 5:15 a.m., Michael Thomas, 37, a patient in Wagner's unit, was arrested on suspicion of homicide, the Ventura County Sheriff's Department reported.
Wagner was found dead by a hospital attendant who had been periodically checking him after the 4 a.m. attack by Thomas, Lt. Joe Harwell said.
"It appears that the two had argued earlier, which resulted in Thomas attacking the victim and knocking him to the ground," Harwell said.
Wagner was examined by the hospital's medical staff and returned to bed, Harwell said.
About an hour after the fight, an attendant noticed that Wagner had stopped breathing. Efforts to revive him failed. Thomas was arrested and taken to Ventura County Jail, where he was being held on $250,000 bail.
Harwell said no weapons were found after the fight, which appeared to have ended quickly.
"Right now the assumption is that the cause of death is something to do with the physical altercation about an hour before," Harwell said.
Harwell and hospital spokesman John Fortner declined to disclose what Thomas and Wagner were being treated for at the hospital.