Aviation Security: DHS and TSA Have Researched, Developed, and Begun Deploying Passenger Checkpoint Screening Technologies, but Continue to Face Challenges, Report to Congressional Requesters [open pdf - 2MB]
From the Highlights: "Since fiscal year 2002, the Transportation Security Administration (TSA) and the Department of Homeland Security (DHS) have invested over $795 million in technologies to screen passengers at airport checkpoints. The DHS Science and Technology Directorate (S&T) is responsible, with TSA, for researching and developing technologies, and TSA deploys them. GAO was asked to evaluate the extent to which (1) TSA used a risk-based strategy to prioritize technology investments; (2) DHS researched, developed, and deployed new technologies, and why deployment of the explosives trace portal (ETP) was halted; and (3) DHS coordinated research and development efforts with key stakeholders. To address these objectives, GAO analyzed DHS and TSA plans and documents, conducted site visits to research laboratories and nine airports, and interviewed agency officials, airport operators, and technology vendors."
Government Accountability Office: http://www.gao.gov