Abdullah was assigned to the Saudi Embassy in Washington DC. Abdullah was head of the World Assembly of Muslim youth a subsidiary of the Muslim World League.
FBI agents wanted to investigate Abdullah and his associate Omar for running terrorist training camps for the Chechen Jihad in the USA as well as other terrorism related offences but the two Bin Laden brothers were under special protection from Justice on the orders on the White House. Saudis in the US already had special privileges that amounted to virtual immunity form US law.
Abdullah bought 3411 Silver Maple Place, Falls Church, VA 22042 from William F Shimonkevitz, a retired Colonel in the USAF.
Abdullah shared Post Office Box 8671 in Falls Church Virgina with Mark A Foster. The Foster's had an address at 105 Travis, Offutt Air Force Base, Omaha Nebraska
A "close associate" of Abdullah's was Mohammed Rafique Quadir Harunani. He had been under investigation for terrorism by the FBI since 1999. A search of Harunani's residences uncovered the phone number of Mohamed Atta's father and sister.