Washington: Future Attribute Screening Technology (FAST), is a US Department of Homeland Security (DHS) programme designed to spot people who are intending to commit a terrorist act. It has in the past few months completed its first round of field tests at an undisclosed location in northeast US, nature.com reports.

How it works

Like a lie detector, FAST measures physiological indicators, ranging from heart rate to the steadiness of a person’s gaze, to judge a subject’s state of mind. Unlike the polygraph, FAST relies on non-contact sensors, so it can measure indicators as someone walks through a corridor at an airport, and it does not depend on active questioning of the subject.

From fiction to fact

The tactic has drawn comparisons with the science-fiction concept of ‘pre-crime’, popularised by the film Minority Report, in which security services can detect someone’s intention to commit a crime. Unlike the system in the film, FAST does not rely on a trio of human mutants who can see the future. But the programme has attracted copious criticism from researchers who question the science behind it. FAST has only been tested in the lab, so successful field tests could lend some data to support the technology.

The problems

DHS’s press release states that tests of FAST involve instructing some people passing through the system to carry out a ‘disruptive act’. Tom Ormerod, a psychologist in the Investigative Expertise Unit at Lancaster University, UK, questions whether such role-playing is representative of real terrorists, and also worries that both passengers and screeners will react differently when they know they’re being tested. “Fill the place with machines that go ping, and both screeners and passengers start doing things differently.”

In lab tests, DHS has claimed accuracy rates of around 70 per cent, but it remains unclear if the system will perform better or worse in field trials. “The results are still being analysed, so we cannot yet comment on performance,” says John Verrico, a spokesman for the DHS.

Some scientists question whether there really are unique signatures for ‘malintent’ — the agency’s term for the intention to cause harm — that can be differentiated from the normal anxieties of travel. “Even having an iris scan or fingerprint read at immigration is enough to raise the heart rate of most legitimate travellers,” says Ormerod.

Steven Aftergood, a senior research analyst at the Federation of American Scientists, thinks the FAST tests will produce a large proportion of false positives, frequently tagging innocent people as potential terrorists and making the system unworkable in a busy airport.

Secrecy over testing

As for where precisely FAST is being tested, that for now remains a closely-guarded secret. The DHS says that although the first round was completed at the end of March, more testing is in the works, and the agency is concerned that letting people know where the tests are taking place could affect the outcome. “I can tell you that it is not an airport, but it is a large venue that is a suitable substitute for an operational setting,” says Verrico.