註釋 To enhance aviation security, the Transportation Security Admin. (TSA) began initial testing in Oct. 2003 of its Screening of Passengers by Observation Techniques (SPOT) program. Behavior Detection Officers carry out SPOT's mission to identify persons who pose a risk to aviation security by focusing on behavioral and appearance indicators. This report reviewed the SPOT program and analyzed: (1) the extent to which TSA validated the SPOT program before deployment; (2) implementation challenges; and (3) the extent to which TSA measures SPOT's effect on aviation security. The report analyzed TSA documents; interviewed agency personnel and subject matter experts; and visited 15 SPOT airports. Charts and tables. 