A320 CREW DIVERTING TO LAX FROM SAN ACCEPTS VISUAL APCH CLRNC TO FOLLOW TFC TO ARPT BUT LATER FINDS OUT FOLLOWING WRONG ACFT.

Narrative

FLT ACR X ON FEB/XA/00 WAS DIVERTING TO LAX DUE TO ARPT CLOSURE IN SAN. FLT WAS ON VECTOR FROM SMO VOR ON REDEYE 2 ARR. CTLR POINTED OUT 11 O'CLOCK TFC AND WE RESPONDED THAT WE HAD TFC IN SIGHT. CTLR TOLD US TO FOLLOW TFC AND CLRED VISUAL APCH TO RWY 6R. WHILE ON BASE LEG; DSNDING TO 3500 FT; CTLR ADVISED THAT WE WERE CUTTING OFF THE TFC WE WERE TO FOLLOW AND TO MAKE AN IMMEDIATE TURN TO 250 DEGS AND DSND TO 2500 FT. WE THEN SAW THE TFC; A SECOND ACFT; ON TCASII. I BELIEVE WE WERE AS CLOSE AS 1-2 MI; 400 FT FROM THE TFC. FACTORS INVOLVED: THIS WAS THE SECOND DIVERSION FOR THIS FLT. THE FIRST HAVING BEEN A MEDICAL EMER INTO DEN. THE HR WAS LATE; ABOUT XA30 AT THE CREW'S BASE. POSSIBLY WE FAILED TO CHK ALL QUADRANTS FOR TFC. POSSIBLY THE TFC WE SAW WAS NOT THAT WHICH WAS POINTED OUT. IN ANY CASE; WE PROBABLY DID NOT EXPECT 2 OTHER ACFT BESIDES US TO BE ON A VISUAL. THE FACT THAT IT WAS DARK; OVER WATER AND TO AN APCH NOT OFTEN FLOWN HAD ME AT LEAST FOCUSED ON THE INSTS AND THE INST PROC AND NOT ON VISUAL SCANNING.