The chairman of the House Homeland Security Committee on Wednesday said that the use of facial recognition technology on American citizens departing the U.S. on international flights is an expansion of authorities granted by Congress to apply the technology to foreign nationals leaving the country to verify they are complying with their visa terms.

Rep. Bennie Thompson (D-Miss.) said that Customs and Border Protection (CBP) has taken its “own initiative” to apply its biometric exit program to U.S. citizens that is “beyond the scope of authority that Congress gave you. Thompson addressed his remarks to John Wagner, deputy assistant executive commissioner of CBP’s Office of Field Operations, during a hearing to examine the Department of Homeland Security’s use of facial recognition and other biometric technologies.

Rep. Bennie Thompson (D-Miss.), chairman of the House Homeland Security Committee.

Thompson asked Wagner to provide his committee the “written policy” that enables the use of facial recognition against U.S. citizens. Wagner said he would.

In his oral and written testimony, Wagner outlined the rationale for applying CBP’s biometric exit program, which was mandated by Congress to help verify the departure of foreign nationals from the U.S. per a recommendation of the 9/11 Commission. Wagner said that earlier biometric exit technology evaluations, combined with the layout of airport departure gates in the U.S. and the needs of aviation stakeholders, demonstrated that the only efficient way to do the biometric checks was to obtain face images of both foreign nationals and U.S. citizens.

The agency also found that facial recognition is the easiest and most traveler friendly way to meet the biometric exit mandate. Where the technology is deployed, airlines are, or are considering, using the facial recognition check in lieu of a traveler having to present their boarding pass.

CBP, working with its airport and airline stakeholders, so far has only deployed cameras at a select number of airports and departure gates. They agency wants its stakeholders to pay for the front-end systems while it provides the back-end facial matching service.

Under existing laws, Wagner pointed out that the agency has the authority to inspect travel documents to determine whether individuals arriving to and departing from the U.S. are citizens or foreign nationals and that it typically uses manual processes in most cases to ensure that a person “is the true bearer of his or her travel documentation.”

Using facial recognition technology, CBP is “automating” what is currently a manual process, Wagner told the panel.

“We don’t see this as expanding the biometric entry, exit authority, we see this as using the authorities we have to determine the citizenship of an individual entering or departing the U.S.,” he said.

Facial recognition technology has identified six impostors attempting to enter the U.S. with other people’s travel documents, and in two cases with genuine U.S. travel documents, Wagner said.

In his opening statement, Thompson highlighted that “I am not opposed to biometric technology and recognize it can be valuable to homeland security and facilitation. However, its proliferation across DHS raises serious questions about privacy, data security, transparency and accuracy. The American people deserve answers to those questions before the federal government rushes to deploy biometrics further.”

Asked if Thompson is considering legislation related to CBP’s use of facial recognition technology on U.S. citizens, a committee spokesman told Defense Daily via an email reply to query that “It’s probably too early to know.”

U.S. citizens can opt-out of using the facial recognition check at airport departure gates but Thompson said people may not realize this or how do to it. Wagner said CBP understands it can improve the public’s awareness of the opt-out provision.

Photos taken of U.S. citizens at the departure gate are held by CBP for 12 hours in case of a system outage or the need for recovery in a disaster before being deleted, Wagner said.

Thompson also raised concerns with the accuracy of facial recognition systems, highlighting a study last July by the American Civil Liberties Union that tested a system by using photos of all Members of Congress against a database of 25,000 arrest photos. The software matching system “incorrectly” matched 28 members against the database, and “nearly 40 percent of the false matches were people of color,” he said. “This is unacceptable.”

Charles Romine, director of the Information Technology Laboratory at the National Institute of Standards and Technology (NIST), told the committee that a 2018 test by this agency of face matching algorithms used in one-to-many searches found “massive gains in accuracy have been achieved” in the past five years, saying later that accuracy levels are at 99.7 percent. The gains in the matching algorithms are due to improvements in machine learning and artificial intelligence.

In addition to dark-skinned individuals, women are misidentified more than average as well by the face matching algorithms, Thompson said. Romine said sex, race and changes in age have all presented challenges to the algorithms but with advances in technology the demographic effects are “diminishing.”

NIST is currently doing a comprehensive analysis of demographic effects on facial matching software based on recent testing and the results will be published this fall, Romine said.

Wagner said that CBP is getting accuracy rates above 97 percent in its use of the facial recognition systems, which rely on cameras from multiple venders but use matching algorithms provided by Japan’s NEC Corp. as part of the back-end Traveler Verification System. Wagner said that CBP has partnered with NIST to review the agency’s data to validate it.

Asked by Rep. John Katko (R-N.Y.) about the “gaps and limitations” with facial recognition technology, Romine responded that image quality is critical.

“It’s still true,” Romine said. “Garbage in, garbage out for software systems.” In addition to demographic issues, injuries and non-cooperative subjects, which may include an image of a person taken through a windshield or walking and not facing a camera, can impair performance, he said.

Wagner said that CBP is attuned to the need for quality image capture and that if a photo isn’t of sufficient quality, it has to address camera quality and lighting conditions to improve chances for a correct match.

If a person’s photo taken at the gate doesn’t match their passport photo that is stored in the TVS, that individual just has to show their passport and boarding pass for manual review, he said.

CBP hopes to largely complete its rollout of its biometric exit program at airports within the next few years. The agency is also using facial recognition technology at several seaports and is testing the technology at land ports for entry operations in both pedestrian and vehicle environments. In the land evaluations, Wagner said the technology has identified 138 impostors, including 45 that were holding real U.S. travel documents.