CAPPS was an FAA-approved automated system run by the airlines that scored each passenger’s profile to identify those who might pose a threat to civil aviation.The system also chose passengers at random to receive additional security scrutiny.Ten out of the 19 hijackers (including 9 out of 10 on the two American Airlines flights) were identified via the CAPPS system.According to the procedures in place on 9/11,in addition to those flagged by the CAPPS algorithm,American’s ticket agents were to mark as “selectees”those passengers who did not provide correct responses to the required security questions, failed to show proper identification, or met other criteria.See FAA report,“Air Carrier Standard Security Program,”May 2001,pp.75–76;FAA record of interview,Donna
Thompson,Sept.23,2001;Chuck Severance interview (Apr.15,2004);Jim Dillon interview (Apr.15,2004);Diane Graney interview (Apr. 16, 2004). It appears that Atta was selected at random. See Al Hickson briefing (June 8, 2004).

Furthermore, according to the British defense publication Jane’s Land-Based Air Defence, “the American president’s residences in Washington and elsewhere are protected by specialist Stinger teams in case of an aerial attack by terrorist organizations.” [Jane's Land-Based Air Defence, 10/13/2000] Knight Ridder has previously reported “several sources” telling it, “Stinger missiles are in the Secret Service’s arsenal.” [Knight Ridder, 9/12/1994] And according to the London Telegraph, the Secret Service is “believed to have a battery of ground-to-air Stinger missiles” ready to defend the White House. [Daily Telegraph, 9/16/2001]