The transportation security officer at Raleigh-Durham International Airport looked up from her X-ray monitor and asked Tim McCullen what was in his briefcase.''I said, 'Oh gosh, did I leave my knife in it?'" recalls McCullen, a Beaufort, N.C., businessman. "She said, 'It doesn't look like a knife.' I said, 'Oh jeez, did I leave my gun in it?'"Yes.McCullen had gone to the airport on Feb. 14 packing a .45 Taurus revolver loaded with .410 shotgun shells, a formidable weapon marketed as "The Judge." He says he meant to leave it at home.