At the last line of defense, America's borders, Customs employs a variety of technological systems to detect and interdict WMD. Before cargo arrives in this country, Customs uses sophisticated computer systems as well as intelligence data to screen the cargo and determine which shipments are high-risk. Upon arrival, all cargo identified as high-risk for security purposes is subject to further scrutiny by Customs.
To examine these shipments, Customs uses a range of technology, including gamma ray and x-ray inspection systems. Radiation detection technology, including radiation pagers, portal detection systems, and isotope identifiers also form part of this arsenal, which is expanding daily. Next year, for example, Customs hopes to have a total of 8,500 radiation pagers and 150 large-scale X-ray and gamma ray systems in place. Other systems are being bolstered as well.