Searching Passengers' Faces For Subtle Cues to Terror

Looking for signs of "stress, fear and deception" among the hundreds of passengers shuffling past him at Orlando International Airport one day last month, security screener Edgar Medina immediately focused on four casually dressed men trying to catch a flight to Minneapolis.

The TSA also plans to train screeners in the art of observing slight facial movements that indicate a person is lying.

The teams have referred more than 40,000 people for extra screening since January 2006. Of those passengers, nearly 300 were arrested on charges including carrying concealed weapons and drug trafficking. TSA officials will not say whether the screeners have helped nab potential terrorists, but they say terrorists and other lawbreakers exhibit the same behavioral clues.