The Orange County coroner's office said Sunday that it will not know what caused the death of a 39-year-old Mission Viejo man until toxicology tests are completed, which could take several weeks.
The man, Steven Linscott Hammett, was found dead in his bed Saturday several days after he was involved in a fight with a 74-year-old male friend of his mother.
A sheriff's spokesman said Hammett showed trauma to his face and upper body, a result of the Tuesday fight with the unidentified man, who lives nearby.
The older man had been summoned by Hammett's mother, who lived with her son in the Costa del Sol retirement community.
The mother and son were reportedly arguing after Hammett refused to come to dinner because he was using the computer, police said.