USA TODAY | September 22, 2008
By Thomas Frank

UPPER MARLBORO, Md. — A scene from the airport of thefuture: A man's pulse races as he walks through a checkpoint. His quickenedheart rate and heavier breathing set off an alarm. A machine senses his skintemperature jumping. Screeners move in to questionhim.
Signs of a terrorist? Or simply a passenger nervousabout a cross-country flight?

It may seem Orwellian, but on Thursday, theHomeland Security Department showed off an early version of physiologicalscreeners that could spot terrorists. The department's research division isyears from using the machines in an airport or an office building— if they even work at all. But officials believe the ideacould transform security by doing a bio scan to spot dangerouspeople.

Critics doubt such a system can work. The idea, they say,subjects innocent travelers to the intrusion of a medical exam.

Thefuturistic machinery works on the same theory as a polygraph, looking for sharpswings in body temperature, pulse and breathing that signal the kind of anxietyexuded by a would-be terrorist or criminal. Unlike a lie-detector test thatwires subjects to sensors as they answer questions, the "Future AttributeScreening Technology" (FAST) scans people as they walk by a set ofcameras.

"We're picking up things with sensors that can't necessarily bedetected by the human eye," said Jennifer Martin, a consultant to HomelandSecurity's Science and Technology division.

The five-year project, in itssecond year, is the department's latest effort to thwart terrorism by spottingsuspicious people. The Transportation Security Administration (TSA) has trainedmore than 2,000 screeners to observe passengers as they walk through airports,questioning those who seem oddly agitated or nervous. 

The system wouldbe portable and fast, said project manager Robert Burns, who envisions machinesthat scan people as they walk into airports, train stations or arenas. Thoseflagged by the machines would be interviewed in front of cameras that measureminute facial movements for signs they are lying.

Like the TSA's program,FAST raises reliability questions. Even if machines accurately spot someonewhose heart rate jumps suddenly, that may signal the agitation of learning aflight is delayed, said Timothy Levine, a Michigan State University expert ondeceptive behavior.

"What determines your heart rate is a whole bunch ofreasons besides hostile intent," Levine said. "This is the whole reasonbehavioral profiles don't work."

John Verdi, a lawyer at the ElectronicPrivacy Information Center, calls physiological screening a "medical exam" thatthe government has no business conducting. "This is substantially more invasivethan screening in airports," Verdi said.

Burns said the measurementswould not be stored and would give a quick read on someone. Previous research,Burns added, has found that people planning to cause harm act differently fromthe anxious or annoyed.

To pinpoint the physiological reactions thatindicate hostile intent, researchers have set up two lab-like trailers on anequestrian center outside Washington, D.C. Science and Technology recruited 140local people with newspaper and Internet ads seeking testers in a "securitystudy." Each person receives $150.

On Thursday, subjects walked one byone into a trailer with a makeshift checkpoint. A heat camera measured skintemperature. A motion camera watched for tiny skin movements to measure heartand breathing rates.

As a screener questioned each tester, five observersin another trailer looked for sharp jumps on the computerized bands thatdisplay the person's physiological characteristics.

Some subjects wereinstructed in advance to try to cause a disruption when they got past thecheckpoint, and to lie about their intentions when being questioned. Thosepeople's physiological responses are being used to create a database ofreactions that signal someone may be planning an attack. More testing isplanned for the next year.