The latest in facial recognition technology enabled security agents at a Washington area airport to catch a passenger trying to sneak into the United States using somebody else’s passport.

The technology, which uses a biometric system to compare the traveler’s face to the picture displayed in his or her passport, had only been in place at the airport for three days when it caught the impostor.

“The new facial recognition technology virtually eliminates the ability for someone to use a genuine document that was issued to someone else,” said Casey Durst, director of the U.S. Customs and Border Protection Baltimore Field Office.

Biometric identification is a futuristic-sounding phrase for the concept of identifying someone based on a unique biological feature, such as DNA, face or voice pattern. In fact, biometric identification has been around since the 1880s, when fingerprints were first used to confirm an identity in court. New and different kinds of biometric identification methods are important tools used by law enforcement today.

The facial-comparison system is important because matching people’s faces to their identification photograph can be trickier than it sounds. When a person loses weight, gets a haircut or starts wearing glasses, it can be hard for agents to be sure that the person is presenting their own ID.

Now, using new facial-comparison biometric technology, the border agents are able to take the guesswork out of when to let someone pass who is presenting his own passport and when to stop identity frauds and impersonators.

The facial-comparison technology is part of a program being rolled out in 14 airports across the United States.