Behavior detection officers are on active duty at dozens of airports throughout the U.S according to SeattlePI; they're looking for unusual behaviors, facial expressions or questionable emotions and reactions during brief interactions with passengers during the standard screening process.Screening Passengers by Observation Technique (SPOT) was designed by the TSA to stop terrorist activity. Carl Maccario who helped design the program said, "We're looking for behavior indicators that show a certain level of stress, fear or anxiety above and beyond that shown by an anxious member of the traveling public."
Since January 06' the program has identified 70,000 people for the secondary screening, and made 600-700 arrests for a variety of charges.