"Our report starts with a description of the current border control procedures for admitting people into the United States--issuing visas to citizens of other nations and passports to U.S. citizens and inspecting travelers at the ports of entry. Next, the report describes how biometric technologies work, including the different types of biometric technologies, their levels of maturity, and their operating and performance characteristics. We present four possible scenarios in which biometrics might be applied to current U.S. border control procedures. For each scenario, we analyze some of the costs, benefits, and risks associated with implementation. Finally, the report sums up certain policy implications and challenges to be faced if a biometric system is to be designed and deployed for border security. A number of appendixes provide details on the major biometric technologies."
Government Accountability Office (GAO): http://www.gao.gov/