Body scan

Technologies to read the terrorist mind

Physical search technologies can always been fooled, it seems. So is layered psychological security the next big development in counter-terrorism?

He was quickly dubbed 'the underpants bomber'. Umar Farouk Abdulmutallab tried to blow up a flight from Amsterdam to Detroit on 25 December 2009 by igniting explosive powder sewn into his underwear. He was overpowered by his fellow passengers, although the attempt would have failed anyway, as he had set fire to his trousers, rather than the explosive.

Farcical or not, it was the nearest thing to a successful terrorist attack on civil aviation in years. It made big headlines and governments responded by rolling out new, tougher security measures at airports, including the infamous new body scanners.

Many people will by now be familiar with body scanners, which bounce X-rays off people, penetrating their clothing to reveal concealed objects. The scanners have become common in the US, and in the UK the bulky step-in booths are already installed at Gatwick, Manchester and Heathrow airports as a kind of enhanced security option to the decades-old metal scanners. The point about the new scanners is that they are supposed to catch terrorists who smuggle non-metallic items in their clothing, such as powders or ceramic knives; in short, another 'underpants bomber'.

The expensive scanners, though, have already been criticised for missing the items they are supposed to spot, due to the fact that the rays will not always penetrate thick folds of clothing. Neither can they penetrate skin, thereby missing bomb material that may be hidden inside body cavities.

Moreover, the US Transport Security Administration's (TSA) chief recently admitted that the new body scanners may not even have caught the actual bomber. A researcher from a German TV show managed recently to smuggle through a thermite bomb strapped to his leg without it being flagged up on the monitoring screen, and there are even less detectable threats ahead.

The US has been on high alert against a revenge terrorist attack from Al Qaeda since leader Osama Bin Laden was killed by US forces in May. According to the TSA, the new big threat is bombs surgically implanted into buttocks, stomachs or breasts, which could then be detonated by mobile phone. A national security official told Reuters in July this year that the US has received 'credible intelligence' that Al Qaeda's affiliate in Yemen is working on methods to plant bombs inside operatives.

Such a threat would arguably render the €150,000 scanners redundant and back up security expert Bruce Schneier's contention that politicians have just been pandering to the 'something must be done' brigade with an expensive bit of kit.

Behavioural technology

The need to stay one step ahead of terrorist tactics has led researchers to think laterally. Rather than endlessly developing fresh technologies to try to detect concealed bombs, perhaps it is time to focus on any tell-tale physiological indicators that may reveal criminal intent.

There are dozens of multi-million euro projects in FP7, the €50bn, seven-year EU science plan devoted to security issues. They have obscure, techy-sounding names like INDECT, ADABTS and HUMABIO. They have mushroomed since security research became the EU's hot new science focus in 2008, often in collaboration with Israel.

Picture the scene at Heathrow in the year 2020. A man walks through the airport entrance. Under the ADABTS project, every passenger is caught on camera, glancingly. But without the man knowing, the camera has decided it will stay with him. A complex set of automated algorithms looking at gestures – the way he licks his lips, maybe – has determined that he may be a risk.

Once singled out as suspicious, the passenger can be tracked from camera to camera as he moves through the airport. Perhaps he gives off further suspicious signals: going to the toilet several times, or failing to stop for a coffee. When the suspect lines up in the security queue, involuntary fidgeting, pupil dilation, respiration and heartbeat detectors may flesh out initial suspicions. The technology might be based on low-energy lasers and carpets with motion detectors.

These detectors could be complemented by area-wide body scanners currently under development, which, unlike those currently in operation, scan many people simultaneously, allowing security officers to have more information at the security check.

If all these signals add up to a suspicious picture, security officials can take a suspect passenger aside: there is a wealth of further information at the authorities' disposal such as telephone, fingerprint and DNA records.

Another EU project, INDECT, works by searching the Internet for information about suspects drawn from websites, forums, Usenet groups, file servers, P2P networks and individual computer systems.

The passenger's arrival by car, tracked via roadside CCTV cameras and automatic vehicle-number detection software, offers further clues as to a suspicious person's identity. For airport staff, a system of gait detectors is being developed to ensure that only authorised personnel enter secure areas.

The monitoring of all passengers could also take place airside as security becomes an airport-wide matter. Behavioural detection would be complementary to the body scanner/metal archway/hand-luggage X-ray as part of a concept known as 'layering' – the hope being that at least one of the technologies will stop any threat.

Terrorist guinea pigs

All this is not without its difficulties, and the scenario just sketched is years away in reasearch-and-development terms. One major challenge, says Gunther Schumacher of the European Commission's Joint Research Centre, is perfecting the technology when you can't test it on people who really are planning to blow up a plane.

'Is that person nervous because he is a terrorist, is of a nervous disposition generally, or because he is worried about missing the plane?' he says.

It is important to find individuals' baseline heartbeat and pupil dilation values and then subject them to stimuli to see how they react. It's not the baseline, which may be high or low, that matters, but the change in response to a prompt. That prompt would perhaps take the form of questioning by security officials. If the heartbeat soars, you have a suspect, and he or she could then become the subject of further investigation.

One problem is that the method is a slow one and presupposes that every single passenger will be questioned by security officials about destination and travel plans, to see if that anxiety spike does occur. The last thing the airline industry, beset by rising fuel costs and ash cloud bans, wants is longer security queues.

An Israeli company, WeCU (pronounced 'we see you') technologies, has come up with a proposal to counter Israel's significant terrorism vulnerability: automated prompting. Rather than relying on security officials to identify a nervous passenger, subliminal images or provocative phrases are flashed up at the automated check-in desk as the passenger verifies his details to get his boarding card.

The company's theory suggests that a would-be jihadist is likely to betray a significant physiological reaction to the words 'Islamic jihad' or to a picture of Osama bin Laden, whereas an innocent passenger would not.

False positives

So is this a solution? The EU-funded project coordinators are very tight-lipped, but early trials in a similar US programme show that the number of false positives is still great, and the developers are working on improvements. The Israeli option, assuming it were shown to work, would clearly raise further ethical concerns about ethnic profiling if it were applied outside of a very specific threat scenario. It has not yet been widely tested. A human alternative, using security officers' trained judgement rather than an electronic eye, has proved little more effective.

The SPOT programme has been going on at US airports since 2006, with security officers mingling in crowds, trying to check out suspicious behaviour without electronic monitoring, just by looking at the person. More recently Heathrow has launched a trial.

The US experience shows just how difficult it is to read emotions correctly.

The theory of micro-gestures, that people reveal the true inner feelings through small unintentional facial tics, developed by one Dr Paul Ekman, has been recently popularised in Malcolm Gladwell's best-selling science books. Researchers have studied hundreds of videos of test interviews – frame by frame, 30 frames a second, each video up to 10 minutes long – so analysts can catalogue 'micro-facial emotional leakages'.

In the last four years, four billion Americans have travelled by air; 200,000 of them have been stopped and taken in for further questioning: 1,700 were arrested, but the individuals netted had other activities to their name for which arrest warrants had already been issued, and it's not clear any single one could be linked to terrorism. One survey called for further research to determine whether security officers, stopping a random number of Americans, would not have resulted in the same proportion of arrests.

Still, researchers are undeterred by early failures, and some enthusiasts have big plans for the technology if it does work out. Its expansion possibilities are limitless: streets, sports stadiums, pubs. But before such a plan could ever become reality, far more CCTV cameras would have to be networked and they would have to deliver a higher frame rate than the current 2fps. The INDECT website says: 'The list of objectives does not include any kind of global monitoring of any society.'


Behavioural detection technology – monitoring the whole gamut of behaviour from suspicious toilet visits to heightened heartbeats – could be a useful tool in the fight against terrorism, but its implementation is some way off and raises questions. Not just privacy and integrity. Could terrorists one day learn how to fake their behaviour? A bit of scepticism is in order.

Large corporate interests are involved in the security industry, and the 'securocrat lobby' has a powerful influence on our politicians. And the past history shows a litany of ambitious projects that promised much and delivered little, with the general public picking the tab up along the way in the form of higher airline ticket prices.

In 2004, the next big thing was supposed to be 'puffer machines' – so called because they blew air on to passengers to dislodge any explosive particles – that were celebrated as the 'no pat-down' option. But in 2007, a TV news crew walked through a detector sprayed with explosives and failed to set it off; the machines suffered from false alarms,'frequent breakdowns and high maintenance costs. In the end, only a quarter of the dozen $80,000 machines, purchased by the US government, were ever used, and they were formally discontinued at the end of 2009. *

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