The Aviation and Transportation Security Act (ATSA), enacted in November 2001, created TSA and gave it responsibility for securing all modes of transportation. As part of this responsibility, TSA oversees security operations at the nation’s more than 400 commercial airports, including establishing requirements for passenger and checked baggage screening and ensuring the security of air cargo transported to, from, and within the United States. TSA has operational responsibility for conducting passenger and checked baggage screening at most airports, and has regulatory, or oversight, responsibility, for air carriers who conduct air cargo screening. While TSA took over responsibility for passenger checkpoint and baggage screening, air carriers have continued to conduct passenger watch-list matching in accordance with TSA requirements, which includes the process of matching passenger information against federal watch-list data before flights depart. TSA is currently developing a program to take over this responsibility from air carriers for passengers on domestic flights, and plans to assume from the U.S. Customs and Border Protection (CBP) the pre-departure name- matching function for passengers on international flights traveling to or from the United States. According to DHS’s budget execution reports and TSA’s congressional budget justifications, TSA received appropriations for aviation security that total about $26 billion since fiscal year 2004. During fiscal year 2004— the first year for which data were available—TSA received about $3.9 billion for aviation security programs, and during fiscal year 2008, received about $6.1 billion. The President’s budget request for fiscal year 2009 includes about $6.0 billion to continue TSA’s aviation security activities. This total includes about $5.3 billion specifically designated for aviation security and about $0.76 billion for aviation-security related programs, such as Secure Flight, and mandatory fee accounts, such as the Aviation Security Capital Fund. Figure 1 identifies reported aviation security funding for fiscal years 2004 through 2008. TSA is also responsible for securing surface modes of transportation, including passenger and freight rail, mass transit, highways, commercial vehicles, and pipelines, in partnership with other federal entities, state and local governments, and the private sector. According to TSA congressional budget justifications, TSA received appropriations for surface transportation security that totaled about $175 million since fiscal year 2005. During fiscal year 2005—the first year for which data were available—TSA received about $36 million for surface transportation security programs. TSA further received $52 million during fiscal year 2006, $41 million during fiscal year 2007, and $47 million during fiscal year 2008 for securing surface modes of transportation. The President’s budget request for fiscal year 2009 includes about $37 million, about $10 million less than last year’s appropriation, to continue TSA’s surface transportation security activities, including conducting compliance inspections, developing best practices and standards, assessing security vulnerabilities, establishing baseline data against which to evaluate minimum-security standards, and providing domain awareness training. One of the most significant changes mandated by ATSA was the shift from the use of private-sector screeners to perform airport screening operations to the use of federal screeners (now referred to as TSOs). Prior to ATSA, passenger and checked baggage screening had been performed by private screening companies under contract to airlines. ATSA established TSA and required it to create a federal workforce to assume the job of conducting passenger and checked baggage screening at commercial airports. The federal screener workforce was put into place, as required, by November 2002. Passenger screening is a process by which personnel authorized by TSA inspect individuals and property to deter and prevent the carriage of any unauthorized explosive, incendiary, weapon, or other dangerous item into a sterile area or onboard an aircraft. Passenger screening personnel must inspect individuals for prohibited items at designated screening locations. The four passenger screening functions are X-ray screening of property, walk-through metal detector screening of individuals, hand-wand or pat- down screening of individuals, and physical search of property and trace detection for explosives. Typically, passengers are only subjected to X-ray screening of their carry-on items and screening by the walk-through metal detector. Passengers whose carry-on baggage alarms the X-ray machine, who alarm the walk-through metal detector, or who are designated as selectees—that is, passengers selected by the Computer Assisted Passenger Pre-Screening System (CAPPS) or other TSA-approved processes to designate passengers for additional screening—are screened by hand-wand or pat-down and have their carry-on items either screened for explosives traces or physically searched. Checked baggage screening is a process by which authorized security screening personnel inspect checked baggage to deter, detect, and prevent the carriage of any unauthorized explosive, incendiary, or weapon onboard an aircraft. Checked baggage screening is accomplished through the use of explosive detection systems or explosive trace detection systems, and through the use of approved alternative means, such as manual searches and canine teams when the explosive detection or explosive trace detection systems are unavailable. The passenger and checked baggage screening systems are composed of three elements: the people (TSOs) responsible for conducting the screening of airline passengers and their carry-on items and checked baggage, the technology used during the screening process, and the procedures TSOs are to follow to conduct screening. Collectively, these elements help to determine the effectiveness and efficiency of passenger and checked baggage screening operations. Air cargo ranges in size from one pound to several tons, and in type from perishables to machinery, and can include items such as electronic equipment, automobile parts, clothing, medical supplies, other dry goods, fresh cut flowers, fresh seafood, fresh produce, tropical fish, and human remains. Cargo can be shipped in various forms, including large containers known as unit loading devices that allow many packages to be consolidated into one container that can be loaded onto an aircraft, wooden crates, assembled pallets, or individually wrapped/boxed pieces, known as break bulk cargo. TSA’s responsibilities for securing air cargo include, among other things, establishing security rules and regulations governing domestic and foreign passenger air carriers that transport cargo, domestic and foreign all-cargo carriers that transport cargo, and domestic indirect air carriers. TSA is also responsible for overseeing the implementation of air cargo security requirements by air carriers and indirect air carriers through compliance inspections, and, in coordination with DHS’s S&T Director, for conducting research and development of air cargo security technologies. Air carriers (passenger and all-cargo) are responsible for implementing TSA security requirements, predominantly through a TSA-approved security program that describes the security policies, procedures, and systems the air carrier will implement and maintain in order to comply with TSA security requirements. Air carriers must also abide by security requirements issued by TSA through security directives or emergency amendments to air carrier security programs. Air carriers use several methods and technologies to screen domestic and inbound air cargo. These include manual physical searches and comparisons between airway bills and cargo contents to ensure that the contents of the cargo shipment matches the cargo identified in documents filed by the shipper, as well as using approved technology, such as X-ray systems, explosive trace detection systems, decompression chambers, explosive detection systems, and certified explosive detection canine teams. Under TSA’s security requirements for domestic and inbound air cargo, passenger air carriers are currently required to randomly screen a specific percentage of non exempt air cargo pieces listed on each airway bill. All-cargo carriers are required to screen 100 percent of air cargo that exceeds a specific weight threshold. As of October 2006, domestic indirect air carriers are also required, under certain conditions, to screen a certain percentage of air cargo prior to its consolidation. TSA, however, does not regulate foreign freight forwarders, or individuals or businesses that have their cargo shipped by air to the United States. Under the Implementing Recommendations of the 9/11 Commission Act of 2007, DHS is required to implement a system to screen 50 percent of air cargo transported on passenger aircraft by February 2009, and 100 percent of such cargo by August 2010. The prescreening of airline passengers who may pose a security risk before they board an aircraft is one of many layers of security intended to strengthen commercial aviation. One component of prescreening is passenger watch-list matching—or the process of matching passenger information against the No-Fly and Selectee lists to identify passengers who should be denied boarding or who should undergo additional security scrutiny. Aircraft operators are currently responsible for checking passenger information against the No-Fly and Selectee lists to identify passengers who should be denied boarding or who should undergo additional security scrutiny. To further enhance commercial aviation security and in accordance with the Intelligence Reform and Terrorism Prevention Act of 2004 (IRTPA), TSA is developing a program to assume from air carriers the function of matching passenger information against government-supplied terrorist watch-lists for domestic flights. Secure Flight is the program through which TSA plans to meet this requirement. Following domestic implementation, TSA, through Secure Flight, plans to assume responsibility from CBP for watch-list matching of passengers on international flights bound to and from the United States. Secure Flight’s mission is to enhance the security of commercial air travel by: eliminating inconsistencies in current air carrier watch-list matching reducing the number of individuals who are misidentified as being on the No Fly or Selectee list, reducing the risk of unauthorized disclosure of sensitive watch-list information, and integrating the redress process so that individuals are less likely to be improperly or unfairly delayed or prohibited from boarding an aircraft. TSA plans to implement Secure Flight in three releases. During Release One, completed in March 2008, TSA developed and tested the Secure Flight system. During Release Two, scheduled to be conducted from April 2008 through August 2008, TSA plans to begin parallel testing with air carriers during which both Secure Flight and air carriers will perform watch-list matching.