All the alleged 9/11 hijackers reportedly check in at the airports from where they board Flights 11, 175, 77, and 93. [9/11 Commission, 7/24/2004, pp. 1-4; 9/11 Commission, 8/26/2004, pp. 27, 89, 93] Since 1998, the FAA has required air carriers to implement a program called the Computer Assisted Passenger Prescreening System (CAPPS). This identifies those passengers who might be a security risk, based upon suspicious behavior such as buying one-way tickets or paying with cash. CAPPS also randomly assigns some passengers to receive additional security scrutiny. If a particular passenger has been designated as a “selectee,” this information is transmitted to the airport’s check-in counter, where a code is printed on their boarding pass. At the airport’s security checkpoints, selectees are subjected to additional security measures. [US News and World Report, 4/1/2002; 9/11 Commission, 1/27/2004; US Congress, 3/17/2004; 9/11 Commission, 8/26/2004, pp. 2, 85] Their baggage is to be screened for explosives or held off the plane until they have boarded. Supposedly, the thinking behind this is that someone smuggling a bomb onto a plane won’t get onto that same flight. According to the 9/11 Commission, nine of the 19 hijackers are flagged by the CAPPS system before boarding Flights 11, 175, 77, and 93. [Washington Post, 1/28/2004; 9/11 Commission, 7/24/2004, pp. 84; United States of America v. Zacarias Moussaoui, a/k/a Shaqil, a/k/a Abu Khalid al Sahrawi, Defendant, 3/6/2006] In addition, Mohamed Atta was selected when he checked in at the airport in Portland, for his earlier connecting flight to Boston (see 5:33 a.m.-5:40 a.m. September 11, 2001). All of the hijackers subsequently pass through security checkpoints before boarding their flights. [9/11 Commission, 7/24/2004, pp. 1-4]