NMAC BTWN SMA AND UNKNOWN ACFT ATA INTRUDER.

Narrative

A LOW WING PLANE WAS VIOLATING REPUBLIC'S AIRSPACE. THE TWR WAS CALLING OUT THIS PLANE TO OTHER TFC AND STATING THAT THEY WERE NOT IN CONTACT WITH IT. THE TWR WAS ALSO ASKING ANOTHER PLT IF THEY COULD IDENT IT. I WAS HDG S TOWARDS THE ARPT AND THE OTHER PLANE WAS HDG N AWAY FROM IT. THE TWR TOLD ME TO TURN W ONCE I PASSED THE LONG ISLAND EXPRESSWAY. THIS IS A LOT EARLIER THAN USUAL FOR ENTERING THE R DOWNWIND FOR RWY 32. AND WOULD PUT ME N OF THE ARPT BY 5-6 MI (INSTEAD OF ENTERING A R DOWNWIND). I THINK THE TWR DID THIS SO I WOULD 'INTERCEPT' THE UNKNOWN ACFT AND IDENT ITS TYPE. ONCE THE PLANE REACHED THE LONG ISLAND EXPRESSWAY; IT TURNED INTO ME AND THE TWR ASKED ME WHETHER I SAW IT AND WHAT TYPE IT WAS. I HAD A HARD TIME IDENTING IT BECAUSE I WAS FLYING INTO THE SUN WHICH WAS LOW. WE WERE ABOUT 1/2 MI AWAY FROM EACH OTHER AND BOTH AT 1500 FT MSL. I ALSO WASN'T SURE HE TURNED INTO ME BECAUSE OF THE SUN; AND I THOUGHT HE WOULDN'T DO THAT BECAUSE IT WAS STUPID AND HE MIGHT HIT ME. AFTER ABOUT A SECOND OR 2 AFTER HE COMPLETED HIS TURN; I REALIZED HE DEFINITELY WAS FLYING TOWARDS ME. I CUT THE PWR AND DIVED DOWN AND HE PASSED OVER ME. DURING THE DIVE THE TWR ASKED ME TO TRY TO IDENT HIM; BUT I COULDN'T BECAUSE I WAS TRYING TO GET UNDERNEATH HIM. IF THE TWR TOLD ME TO IDENT HIM BEFORE IT WOULD HAVE BEEN EASIER. I WAS ABLE TO TRACK HIM FROM BEFORE I MET HIM THE NEAR MIDAIR AND SO WOULD HAVE EASILY STAYED FURTHER AWAY AND IDENTED HIM IF THE CTLRS TOLD ME WHAT THEY WANTED EARLIER. ALSO; I'M SURE THE CTLRS EXPECTED HIM TO FLY STRAIGHT AHEAD AND NOT SUDDENLY TURN INTO ME.