The ability to detect hidden explosives and narcotics is important to U.S. national security, and difficulties in finding even a small quantity of explosives concealed aboard an airplane or a shipment of narcotics smuggled through ports of entry represent tremendous challenges to the technology community. While various technologies can be used to detect explosives and narcotics, relatively little equipment has been deployed at airports and ports of entry. Recent events, such as recommendations of a presidential commission on aviation security, have raised questions as to how well U.S. government agencies responsible for developing explosives and narcotics detection technologies are working together. Despite the technology efforts of several agencies, standards have not been established for explosives detection systems, profiling and targeting systems, and the deployment of canine teams at airports. The GAO report notes that the Federal Aviation Administration, the National Security Council, the Office of Management and Budget, and the Department of Transportation are responsible for overseeing or developing explosives detection technologies and that the Office of National Drug Control Policy, the U.S. Customs Service, the Department of Defense, and the Office of Management and Budget are responsible for overseeing or developing narcotics detection technologies. Further, the GAO report emphasizes the importance of coordinating detection technology development efforts and the need to strengthen detection technology development. Comments from several Federal agencies on the development of detection technologies are appended.