A fter the terrorist attacks of September 11, 2001, the federal government developed a unified regimen to identify and list known or suspected terrorists. The regimen has received repeated congressional attention, and this report briefly discusses for congressional policymakers how the U.S. government fashions and uses the Terrorist Screening Database (TSDB) to achieve such an end. It also discusses how the federal government engages in two travel-related screening processes—visa screening and air passenger screening. The Terrorist Screening Database

The Terrorist Screening Database (TSDB, commonly referred to as the terrorist watchlist) lies at the heart of federal efforts to collect and share information with U.S. law enforcement and security agencies about identified people who may pose terrorism-related threats to the United States. It is managed by the Terrorist Screening Center (TSC) and includes biographic identifiers for those known either to have or be suspected of having ties to terrorism. In some instances it also includes biometric information on such people. It stores hundreds of thousands of unique identities. Portions of the TSDB are exported to data systems in federal agencies that perform screening activities such as background checks, reviewing the records of passport and visa applicants, and official encounters with travelers at U.S. border crossings. The Terrorist Screening Center, the Hub of Watchlisting

The TSC, a multi-agency organization administered by the Federal Bureau of Investigation (FBI), maintains the TSDB. These databases include the No Fly List and the Selectee and Expanded Selectee lists for airline passenger screening; the Department of State's Consular Lookout and Support System (CLASS); the FBI's National Crime Information Center (NCIC); the TECS (not an acronym) system for border and port of entry screening; and the military base access and screening system. The Transportation Security Administration (TSA) uses information from the TSDB for aviation security screening. The No Fly List includes identities of individuals who may present a threat to civil aviation and national security. Listed individuals are not allowed to board a commercial aircraft "flying into, out of, over, or within United States airspace; this also includes point-to-point international flights operated by U.S. carriers." (As discussed below, Customs and Border Protection [CBP] screens the passenger manifest before any international flight is allowed to depart to the United States.) The Selectee List includes individuals who must undergo additional security screening before being allowed to board a commercial aircraft. The Expanded Selectee List, an extra security measure developed in response to a failed attempt to trigger an explosive by a foreign terrorist onboard a U.S.-bound flight on December 25, 2009, screens against all TSDB records that include a person's first and last name and date of birth that are not already on the No Fly or Selectee lists. Many visitors, however, enter the United States without nonimmigrant visas through the VWP. Aliens entering through the VWP have been vetted through a system, known as the Electronic System for Travel Authorization (ESTA), that checks them against the TSDB. As with all foreign nationals, CBP inspectors at the port of entry perform background checks and admissibility reviews that draw on information from the TSDB. The Department of State (DOS) specifically uses the Consular Lookout and Support System (CLASS) database, which surpassed 42.5 million records in 2012 and contains a subset of the TSDB. What about travelers from Visa Waiver Program (VWP) countries where their citizens do not need visas to travel to the United States? ESTA draws on records from the TSBD. Air Passenger Risk-Based Screening

TSA has initiated a number of risk-based passenger screening initiatives to focus its resources and apply directed measures based on intelligence-driven assessments of security risk. A cornerstone of TSA's risk-based initiatives created under this authority is the PreCheck program. PreCheck is TSA's latest version of a trusted traveler program. Under PreCheck, participants vetted through a background check process (including screening against terrorist watchlist information) are processed through expedited screening lanes where they can keep shoes on and keep liquids and laptops inside carry-on bags. In November 2010, DHS announced that 100% of passengers flying to or from U.S. airports were being vetted using Secure Flight.
After the terrorist attacks of September 11, 2001, the federal government developed a unified regimen to identify and list known or suspected terrorists. The regimen has received repeated congressional attention, and this report briefly discusses for congressional policymakers how the U.S. government fashions and uses the Terrorist Screening Database (TSDB) to achieve such an end. It also discusses how the federal government engages in two travel-related screening processes—visa screening and air passenger screening. Both processes involve subsets of the Terrorist Screening Database.
The Terrorist Screening Database (TSDB)
The TSDB lies at the heart of federal efforts to identify and share information among U.S. law enforcement about identified people who may pose terrorism-related threats to the United States. It is managed by the Terrorist Screening Center (TSC), a multi-agency organization created by presidential directive in 2003 and administered by the Federal Bureau of Investigation (FBI). The TSDB includes biographic identifiers for those known either to have or be suspected of having ties to terrorism. In some instances it also includes biometric information on such people. It stores hundreds of thousands of unique identities. Portions of the TSDB are exported to data systems in federal agencies that perform screening activities such as background checks, reviewing the records of passport and visa applicants, official encounters with travelers at U.S. border crossings, and air passenger screening.
Foreign Nationals Traveling to the United States
Two broad classes of foreign nationals are issued visas under the Immigration and Nationality Act (INA): immigrants and nonimmigrants. Many visitors, however, enter the United States without visas through the Visa Waiver Program (VWP). Under the VWP, foreign nationals from 38 countries with agreements with the United States—including most countries in the European Union—do not need visas to enter the United States for short-term business or tourism and are instead vetted using biographic information to authenticate and screen individuals.
Screening Aliens
Department of State (DOS) consular officers check the background of all visa applicants in "lookout" databases that draw on TSDB information and other counterterrorism information such as the material housed in the National Counterterrorism Center's Terrorist Identities Datamart Environment. DOS specifically uses the Consular Lookout and Support System (CLASS) database, which surpassed 42.5 million records in 2012. Aliens entering through the VWP have been vetted through the Electronic System for Travel Authorization (ESTA), which checks them against the TSDB. In addition, before an international flight bound for the United States departs from a foreign airport, Customs and Border Protection (CBP) officers screen the passenger manifest. CBP inspectors also perform background checks and admissibility reviews at the ports of entry that draw on information from the TSDB.
Screening at the Transportation Security Administration
The Transportation Security Administration (TSA) has initiated a number of risk-based screening initiatives to focus its resources and apply directed measures based on intelligence-driven assessments of security risk. A cornerstone of TSA's risk-based initiatives is the PreCheck program. PreCheck is TSA's latest version of a trusted traveler program that has been modeled after CBP programs. Under the PreCheck regimen, participants are vetted through a background check process (including screening against terrorist watchlist information). At selected airports, they are processed through expedited screening lanes, where they can keep shoes on and keep liquids and laptops inside carry-on bags.
All passengers flying to or from U.S. airports are vetted using the TSA's Secure Flight program. Secure Flight involves information from the TSDB housed in the No Fly List, Selectee List, and Expanded Selectee List to vet passenger name records. The No Fly List includes identities of individuals who may present a threat to civil aviation and national security. Listed individuals are not allowed to board a commercial aircraft flying into, out of, over, or within U.S. airspace; this also includes point-to-point international flights operated by U.S. carriers. The Selectee List includes individuals who must undergo additional security screening before being allowed to board a commercial aircraft. The Expanded Selectee List was created as an extra security measure in response to a failed attempt to trigger an explosive by a foreign terrorist onboard a U.S.-bound flight on December 25, 2009. It screens against all TSDB records that include a person's first and last name and date of birth that are not already on the No Fly or Selectee lists.