A 16-year-old allegedly pulled the trigger. He called police afterward to report it.
The boy told police he had shot Russell accidentally.
The pair had been playing in a vacant apartment just before.
Police arrested the 16-year-old and plan to present the case to the Contra Costa County District Attorney's office tomorrow.
His name is being withheld because he is a juvenile.
It's the first homicide of the year in Richmond.