May 20, 2024
The Terrorist Watchlist
The Terrorist Screening Dataset (TSDS), more commonly
Verification and Information Sharing: Involves managing
referred to as the Terrorist Watchlist (or the Watchlist) and
records in the TSDS, as well as compiling and exporting
formerly known as the Terrorist Screening Database, is the
special TSDS subsets for various intelligence or law
U.S. government’s consolidated dataset containing
enforcement end users. All nominations for inclusion in the
sensitive, but not classified, law enforcement and national
Watchlist are vetted by analysts at either NCTC or FBI and
security information regarding those who are known to be
then undergo review at TSC to confirm that they meet the
or are reasonably suspected of being involved in terrorist
minimum identifying and derogatory criteria for inclusion.
activities (both domestic and foreign).
TSC regularly reviews data in the TSDS for quality control.
The Terrorist Screening Center
Encounter Management and Identity Resolution: Involves
end users checking individuals or identities they encounter
Administered by the Federal Bureau of Investigation (FBI),
against information from the TSDS. Screening and vetting
and in coordination with the Departments of Homeland
processes can also yield more information on particular
Security (DHS), State (DOS), and Justice, and the Office of
subjects that may be fed back into the Watchlist. The
the Director of National Intelligence (ODNI), the Terrorist
following agencies access the TSDS (or subsets of the
Screening Center (TSC) is a multiagency organization,
TSDS) to support their missions:
created by a presidential directive in 2003, that manages the
Watchlist. Through the Watchlist, TSC provides timely
• Transportation Security Administration – No Fly,
access to identity information regarding known or
Selectee, and Expanded Selectee lists for airline
suspected terrorists (KSTs) for screening partners,
passenger screening (nominations to these subsets of the
including federal, state, and local law enforcement
TSDS must satisfy additional criteria);
agencies; select international partners; and certain private
•
entities (both domestic and foreign). TSC serves as a bridge
U.S. Citizenship and Immigration Services – Fraud
between homeland security, law enforcement, the
Detection and National Security-Data System for
intelligence community, and select international partners
immigration benefits screening;
for the purpose of sharing terrorism-related information.
• U.S. Customs and Border Protection – TECS (not an
ODNI and the National
acronym) system for border and port of entry screening;
Counterterrorism Center
• U.S. Immigration and Customs Enforcement – for
Nominations of KSTs with a nexus to international
investigations related to the removal of noncitizens;
terrorism are sent to the National Counterterrorism Center
• Department of State – Consular Lookout and Support
(NCTC; part of ODNI) for inclusion in their database, the
System for visa adjudication and passport issuance;
Terrorist Identities Datamart Environment (TIDE). If
eligible, nominations are passed from NCTC to TSC for
• FBI’s National Crime Information Center – Terrorist
potential inclusion in the TSDS. TIDE is the U.S.
Screening Center File to support local, state, tribal, and
government’s central repository of information (both
federal criminal justice agencies for day-to-day
classified and unclassified) on international terrorist
operations;
identities. As of October 2020, TIDE contained about 2.5
• Department of Defense (DOD) – for military base
million identities. U.S. persons (both citizens and lawful
screening and access.
permanent residents) account for less than 1% of the total.
TSC does not publish the number of Watchlist identities,
In addition, Watchlist information is shared with select
although media reports indicate that approximately 2
foreign governments and certain domestic and foreign
million KSTs were on the Watchlist at the end of CY2023.
private entities for screening purposes and to assist in
coordination of terrorist threat awareness, assessment, or
Watchlisting Regimen
response.
The federal watchlisting regimen can be divided into three
broad processes:
Civil Liberties and Privacy Protection
TSC is responsible for civil liberties and privacy protection
Watchlisting: Involves the submission of information on
related to the TSDS. Through DHS, individuals can submit
individuals who may qualify for inclusion as KSTs based
a redress inquiry and seek resolution of a complaint related
on collected intelligence or law enforcement investigations.
to denied or delayed airline boarding, repeated additional
In their daily work reviewing raw information or case files,
screening, or issues with entry into the United States. For
staff at U.S. government agencies—dubbed nominators in
discussion of legal issues surrounding the watchlisting
the watchlisting process—identify people suspected of
process, see CRS Legal Sidebar LSB11009, Legal
involvement in terrorist activity. These identities can be
Challenges to the Terrorist Screening Database.
nominated for inclusion in the TSDS and/or TIDE.
https://crsreports.congress.gov
The Terrorist Watchlist
Figure 1. U.S. Counterterrorism Watchlisting Regimen
Source: Based on CRS analysis of FBI, TSC, “Overview of the U.S. Government’s Terrorist Watchlisting Process and Procedures,” as of April
2024; National Counterterrorism Center, “Terrorist Identities Datamart Environment (TIDE),” October 2020; correspondence between CRS
and TSC on September 16, 2020; and Christopher M. Piehota, Director, Terrorist Screening Center, Federal Bureau of Investigation, statement
before the House Homeland Security Committee, Subcommittee on Transportation Security, Hearing: “Safeguarding Privacy and Civil Liberties
While Keeping Our Skies Safe,” September 18, 2014.
Notes: This figure depicts the process of and the agencies involved in watchlisting.
a. The term nomination refers to any proposed change to a TSDS record, including, without limitation, additions of identities, deletions of
identities, downgrades of identities, or adding supplemental information to an existing record.
b. In addition to its use for screening processes, law enforcement agencies use Watchlist information to support investigations.
IF12669
Lisa N. Sacco, Analyst in Illicit Drugs and Crime Policy
https://crsreports.congress.gov
The Terrorist Watchlist
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
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https://crsreports.congress.gov | IF12669 · VERSION 1 · NEW