Small Aircraft; Low Wing; 2 Eng; Retractable Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Distraction; Confusion; Communication Breakdown; Situational Awareness
ATC Issue All Types; Airspace Violation All Types; Conflict Airborne Conflict; Conflict NMAC; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Separated Traffic
Procedure
I'm working Downey sector which handles LAX arrivals RWY 25L.  I also work arrivals into HHR.  I had Aircraft X on a 070 heading south of the RWY 25 localizer for HHR.  Aircraft X was level at 3;000 and I descended him down to 1;600 when he entered my airspace.  LGB Tower called and asked me for a release for Aircraft Y to HHR.  I released the aircraft with the intent to sequence Aircraft Y behind Aircraft X.  LGB Tower says over the shout line; 'I'm trying to get Aircraft Y to tag up on his beacon code;' and then hangs up the shout line. Seconds later; Aircraft Y tags up on the scope; in my airspace; exactly 3.00NM and 500' FT from Aircraft X on a converging course.  The very next sweep the separation was 2.94NM and 300' FT; and I was still not talking to Aircraft Y.  I immediately turn Aircraft X on a 270 heading.  I key up the shout line and tell LGB Tower to switch me Aircraft Y because he is in my airspace and I need to turn him to avoid collision with Aircraft X. When Aircraft Y checks in I climb him to 3;000 and turn him right to 070.  I cleared Aircraft X for his localizer RWY25 approach to HHR from his 270 heading.  I boxed Aircraft Y around and cleared him for the visual approach into HHR.The only thing that I could have done is protect myself from the possibility that an IFR aircraft was going to be in my airspace without a transponder; and not in communication with me.  I fully intended to turn Aircraft Y behind Aircraft X for sequencing to HHR.
SCT Controller describes a loss of separation between a HHR arrival and a LGB departure.