WASHINGTON — A new report concludes that a Department of Homeland Security test program improperly gathers data on Americans when it requires passengers embarking on foreign flights to undergo facial-recognition scans to ensure they haven’t overstayed visas.
The report, released Thursday by researchers at the Center on Privacy and Technology at Georgetown University’s law school, called the system an invasive surveillance tool that the department had installed at nearly a dozen airports without going through a required federal rule-making process.
The report’s authors examined dozens of Homeland Security documents and raised questions about the accuracy of facial-recognition scans. They said the technology has high error rates and is subject to bias, because the scans often fail to properly identify women and African-Americans.
“It’s telling that DHS cannot identify a single benefit actually resulting from airport face scans at the departure gate,’’ said Harrison Rudolph, an associate at the center and an author of the report.
“DHS doesn’t need a face-scanning system to catch travelers without a photo on file,’’ he added. “It’s alarming that DHS still hasn’t supplied evidence for the necessity of this $1 billion program.’’
Homeland Security officials said the program was necessary and fulfilled a decades-old congressional requirement to prevent foreign visitors from overstaying their visas.
John Wagner, deputy executive assistant commissioner at Customs and Border Protection, said American travelers could ask to be inspected other than by a facial scan before boarding flights. He said that at least 90 percent of the scans had correctly identified faces, and that the agency had not encountered gender or racial bias problems with the technology.
“Our job is to meet the mandate and build the system,’’ Wagner said. “The fact that Congress felt strong enough to set aside a billion dollars to get it done speaks to its need.’’
The report comes as officials begin to roll out a biometric exit system that uses face scans in 2018 at all American airports with international flights.
Customs and Border Protection has been testing a number of biometric programs, teaming up with several airlines in Atlanta, Boston, New York, and Washington. It will cost up to $1 billion, raised from certain visa fee surcharges over the next decade.
Customs officials say the biometric system has also produced some successes in the testing and has helped catch people who have entered the United States illegally and are traveling on fake documents. They noted that facial scans and fingerprints — unlike travel documents — cannot be forged or altered and therefore give agents an additional tool to ensure border security.
But Senators Edward J. Markey, Democrat of Massachusetts, and Mike Lee, a Utah Republican, expressed concern about the report’s findings. In a letter to Kirstjen Nielsen, the Homeland Security secretary, the senators urged the department to delay rolling out facial scans until it addresses the privacy and legal concerns identified in the report.
