20 Years at the TSC

Terrorist Screening Center marks two decades of interagency collaboration

Metal trident from the east facing side of the North Tower. 76 Tridents formed the base of each of the Twin Towers. This remaining piece weighs 30 tons and is 40 ft tall.

Metal trident from the east facing side of the North Tower. 76 Tridents formed the base of each of the Twin Towers. This remaining piece weighs 30 tons and is 40 ft tall.


The Terrorist Screening Center sits on a quiet street in Northern Virginia. It’s a nondescript white building that would be easy to overlook as you drive past.

Three flagpoles stand in front, each flying the American flag and one of the state flags of New York, Virginia, and Pennsylvania. A nearby plaque says that these flagpoles were recovered from the site of the World Trade Center after the terrorist attacks of September 11, 2001, and now stand "as a memorial to those whose lives were taken, those who sacrificed themselves selflessly, and as a testament to our nation’s resilience and enduring liberty."

The Terrorist Screening Center, or TSC, was established in direct response to 9/11. Previously, various U.S. government agencies had maintained their own watchlists to further their unique missions, but there was no mechanism in place to share that information across agencies. A 2003 presidential directive required the U.S. Attorney General to establish an organization that would consolidate terrorism screening within the U.S. government and create one federal terrorism watchlist.

The TSC began operating in December 2003 as an interagency center staffed by multiple U.S. government agencies, including the Department of Justice, the Department of Homeland Security (DHS), the Department of State, and the National Counterterrorism Center (NCTC), among others. The FBI supports the TSC’s administrative functions and provides most of its workforce.

"We are truly interagency here," said Michael Glasheen, director of the TSC and an FBI assistant director. "DHS and U.S. Customs and Border Protection are embedded on the watch floor. NCTC and State Department are here. The key to TSC’s success is leveraging the authorities of the supporting federal agencies to negatively impact our adversaries."

The mission of the TSC starts with aggregating information across agencies into the federal terrorism watchlist. This information is provided to authorized investigative, intelligence, and screening agencies to respond if a known or suspected terrorist is encountered within the United States, at its borders, or overseas.

"We are truly interagency here."

- Michael Glasheen, director of the TSC and an FBI assistant director

Terrorist Screening Center - 911 Memorial outside the TSC

An annual 9/11 remembrance ceremony is held at the TSC to honor the lives that were lost in the attacks. The ceremony also serves as a poignant reminder of why the TSC was founded and its mission to continue to protect American citizens.



Watchlist Process

The TSC is part of a multi-agency review process to determine whether an individual should be added to the terrorism watchlist. 

The process begins, explains Glasheen, when "investigators and intelligence collectors—whether it’s FBI, NSA, State, DHS—identify people with some nexus to international terrorism and provide that information to the NCTC, which is run out of the Office of the Director of National Intelligence."

The NCTC maintains a classified database of international terrorism-related information used for intelligence analysis. In cases where the NCTC receives enough information on an individual to meet the watchlist criteria, they verify whether the person is reasonably suspected to be involved in terrorism or terrorist activities. The NCTC then sends the unique identifiers of verified individuals to the TSC.

The TSC reviews each nomination and performs its own verification to determine if an individual meets the established watchlist criteria. There are multiple levels to this process before a decision is made on each nomination.


The TSC is the final arbiter of watchlisting decisions, and it keeps rigorous and continuing quality control measures over the terrorism watchlist to ensure that nominations continue to satisfy the criteria for inclusion and that information offered in support of the nomination is reliable and up to date. Quality control measures include regular reviews and evaluations by the nominating agency, NCTC, and the TSC to verify that each nomination meets the watchlist inclusion criteria.

In addition to maintaining and regularly reviewing the watchlist, the TSC responds to queries from federal, state, and local agencies—as well as certain foreign partners who have information sharing agreements with the United States—for a variety of screening purposes.

"We’re the unclassified system for sharing information," said Glasheen. "The TSC has the authority to accept, maintain, and share identifying information on people who are on the watchlist."

Around-the-Clock Response

The TSC operates 24 hours a day, 365 days a year. Call center staff, who work across three shifts, answer inquiries immediately as they come in. To ensure continuity of operations, a small room next to the call center houses a few bunk beds in case employees can’t travel home between their shifts for some reason, such as inclement weather.

Some inquiries are routine screening procedures. Others are triggered by live encounters, like a police officer calling to report a potential watchlist match of someone they’ve pulled over.

The TSC conducts identity resolution, looking at all available information to verify whether the name that triggered the inquiry is the same person on the watchlist.

"The call center tries to resolve identity resolutions within minutes,” said Glasheen.

The TSC then responds to the inquiry with one of three possible answers: positive match, negative match, or inconclusive.

"We don’t dictate what actions should be taken when a screening agency encounters an individual potentially on the watchlist," said Glasheen. "We say only whether it’s positive, negative, or inconclusive. Then it’s up to the caller, within their own authorities, to determine what actions they take based on that information."

"We don’t dictate what actions should be taken when a screening agency encounters an individual potentially on the watchlist."

- Michael Glasheen

Terrorist Screening Center - 911 World Trade Center debris

Piece of the North Tower antenna that weighs 7500 pounds and is 12.5 ft long. The original antenna weighed 350 tons and was 359 ft long, making the North Tower one of the tallest buildings in the world before 9/11.


Though the TSC’s mission and processes are straightforward, there are often misconceptions about both.

For example, Americans who have experienced additional screening at airports have sometimes reported that they’ve been unfairly placed on the watchlist. Enhanced screening can happen for many reasons unrelated to watchlisting. In fact, U.S. persons make up less than 0.5% of all watchlist records, which are based on terrorism activities only.

Another misperception is that the watchlist is designed to target members of certain communities.

Watchlist nominations are not based on race, religion, ethnicity, or any constitutionally protected activities like the right to free speech, freedom of press, the ability to file for redress with the government, or the ability to peacefully protest.


"The TSC is a screening tool to identify known or suspected terrorists based on an approved set of standards," said Glasheen. "When we get the information, we are the last step in the nominations process. If someone believes they’re being unfairly screened on a regular basis, it’s often because they have a similar name to someone on watchlist."

The TSC also does not have authority to monitor individuals on the watchlist.

"There must be a triggering event for a screening agency to contact the TSC," Glasheen clarified. "For example, if an agency nominated an individual who lives in a foreign country and, three years later, that person applies for a visa to enter the United States, the TSC would get an encounter through State Department that this person might be a match to a watchlist record."

When an identity resolution comes back positive, the TSC call center informs both the triggering agency—in this example, the State Department—and the agency that nominated the individual to the watchlist.

"We are a tool that is available for use by other government agencies within their own authorities," Glasheen added. "The TSC is an extremely important and effective U.S. government entity.

"Our ultimate goal," Glasheen stressed, "is to protect Americans from national security threats."

“Our ultimate goal is to protect Americans from national security threats.”

- Michael Glasheen