The Los Angeles County Sheriff's Department says they believe Gavin Smith was a homicide victim. The death certificate issued Thursday was dated May 1, 2012.
"We have physical evidence of his death," Bill McSweeney, head of the detective bureau, said.
Smith's body has not been found. His car, a Mercedes-Benz, was discovered last year in
a storage unit in Simi Valley.
Investigators have named John Creech, now serving eight years for selling cocaine, as a person of interest in Smith's disappearance.
Creech has also been linked to the unit where Smith's Mercedes was found. He was arrested in 2010 and later pleaded no contest to drug charges.
Smith, 57 when he disappeared, was a basketball star at UCLA and the University of Hawaii. He got into the business side of the movie business after a brief career as an actor and became an executive in the Fox distribution department.
Smith's marriage was in trouble and he had been staying at the home of a female colleague in Ventura County north of Los Angeles. He left the house late in the evening, leaving items like his phone charger behind.