Border security officials have caught a second impostor trying to enter the United States using a new facial comparison biometric system. It is the second time in less than three weeks since the cutting-edge technology was deployed at Dulles Washington International Airport in the Washington, D.C. area that someone has been caught.

U.S. Customs and Border Protection (CBP), says a 26-year-old woman, who arrived on a flight from Ghana, presented a U.S. passport as a returning citizen. Utilizing the facial comparison technology, the CBP officer determined that the traveler was not a match to the passport and referred her for further examination which confirmed that she was a Ghanaian citizen and an impostor.

The woman’s name was not being released while the investigation continues.

Posing as someone else when attempting to enter the United States is a violation of U.S. immigration law that could result in criminal prosecution. Inadmissible criminals and other foreign nationals routinely attempt various means to enter the US including using stolen, purchased or “borrowed” passports.

CBP says its system has a match rate of 99% making it extremely difficult for criminals, terrorists or impostors to enter the country using another person’s identification and travel documents. The 2 second scan enables increased security, faster throughput, and better efficiency, according to authorities.

In the first case, on Aug. 22, an imposter at Washington Dulles that was attempting to enter the United States using a French passport. A search revealed the man’s authentic Republic of Congo identification card concealed in his shoe.

CBP is testing biometric exit at 15 airports across the country.