November 16, 2001 INVESTIGATORS THINK YEMINI MAN WAS MEANT TO BE 20th HIJACKER By MICHAEL MOSS Federal investigators say that they now believe a Yemeni citizen may have been meant to be the 20th hijacker on Sept. 11 but that he failed to get into the United States. The man, Ramzi Omar, also known as Ramsi Binalshibh, is the subject of a worldwide manhunt. The suspected ringleader of the hijackers, Mohamed Atta, tried three times to get Mr. Omar into the United States, The Associated Press reported. Director Robert S. Mueller III of the F.B.I., briefing federal prosecutors on Wednesday, ...