Deputies say three teenagers were seen riding bicycles away from the apartment complex after the shooting, but their investigation later identified Valenzo as the suspected gunman.
Valenzo remains at large and deputies are asking for the public's help in finding him.
Valenzo is described as Latino, about 5 feet 3 inches, 160 pounds, with dark hair and eyes. Police say he should be considered armed and dangerous.
Anyone with information as to his whereabouts is asked to call sheriff's detectives at (323) 890-5604 or (323) 890-5549.