A 26-year-old man showed a French passport upon arrival from Sao Paulo, Brazil, but the software flagged his face as not matching the passport photo, the CBP said.
He was questioned, and a search revealed his real ID -- from the Republic of Congo -- in his shoe.
The US Attorney's Office decided against prosecuting the man and he left the US on Wednesday night, the CBP said Friday. His name wasn't released.
CBP said it was the first time an impostor had been caught using this tech, which had only been in use there since Monday.
"Terrorists and criminals continually look for creative methods to enter the US including using stolen genuine documents," Casey Durst, director of the CBP's Baltimore office, said in a statement. "The new facial recognition technology virtually eliminates the ability for someone to use a genuine document that was issued to someone else."
There are now 14 "early adopter" airports using the facial recognition system to screen arriving international passengers, according to the CBP. The agency said it's assessing whether it could be part of a future process in which travelers use biometrics instead of physical boarding passes or IDs to get through security.
Outside the US, Australia has taken this tech to the next level by spearheading efforts to implement a passport-free facial recognition system that confirms a traveler's identity by matching his or her face against stored data.
First published, Aug. 24 at 6:43 a.m. PT. Update, 8:26 a.m. PT: Clarifies the man's status, according to the CBP.
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