Aviation accident LAX97FA164

inadequate service provided by the TRACON controller, by issuing a radar vector to the Boeing 737 flight, which resulted in inadequate separation from a Beech 99 that the controller had just terminated from radar service; and failure of the controller to provide adequate traffic/safety advisories to the Boeing 737 crew. Additional causes were the delayed initiation of a TCAS evasive maneuver by the first officer (copilot) of the Boeing 737, and failure of the Boeing 737 Captain to adequately supervise the response of the first officer to the TCAS resolution advisory. Inadequate visual lookout by the Beech 99 pilot was a related factor.