NBA Commissioner David Stern also expressed sympathies to the Sterlings.
"On behalf of the NBA family, we extend our deepest and most heartfelt condolences to Donald and Shelly Sterling on the loss of their son, Scott," Stern said.
The death at a beachfront apartment building on Pacific Coast Highway was discovered after a friend of Scott Sterling called police after not hearing from him for several days, according to a statement from the Los Angeles County Sheriff's Department. Deputies found the body and paramedics pronounced him dead at the scene.
"Sheriff's homicide and Los Angeles County coroner's personnel at this time believe that Sterling died of an apparent drug overdose," the statement said.
Dietz said the death appeared to be accidental, but an autopsy was planned to determine the exact cause of death.
In 1999, the then-19-year-old Sterling was arrested for shooting his friend with a shotgun. Beverly Hills police said Philip Scheid was shot in the legs during an argument at Donald Sterling's mansion.
Scheid said he was shot from behind while running away. Sterling said he fired in self-defense after Scheid approached him with a knife. The county district attorney's office declined to file criminal charges, citing credibility problems with the victim.
AP Sports Writer Antonio Gonzalez in Oakland, Calif., contributed to this report.