Hostile intent?

Imagine a world in the future where you could know in advance if someone was about to commit a crime. Imagine now the USA homeland security project code name Hostile Intent. This project looks to develop methods of screening people in airports and trying to predict those who are up to no good before they get up to it. The system has not been built yet but there are some researchers around the world who think it might be possible, others who think it isn't possible, and others who think it would be a bad idea even if it was possible.

I can tell

The system would work using a whole range of measurements taken on the people passing through airports, looking for example at their facial expressions, or body temperature, trying to piece together the clues that would indicate whether this person had some more sinister intent in the future. Those who support this idea point to the ability of trained investigators to recognise so called micro-expressions in people's faces. When you're trying to hide your true feelings they can leak out in very short bursts onto your face, a bit like a gamblers' 'tell' - they show your true intent.

Would I lie to you?

When we are under stress because we are hiding something our body tends to go into overdrive, increased respiration and heartbeat, and our skin starts to sweat. These are the signs that are picked up by a lie detector, or to give it its proper name the polygraph (as it's measuring many things). There are many legal cases in the US where lie detector evidence has played a part in a conviction, but the technique is still controversial in many other parts of the world. It needs trained people to analyse the output and a calm environment to do the testing in. That is important so that any stress can be put down to the person lying and not worrying about something else. This could be hard to achieve in a busy airport. My stress may be about possibly missing my flight rather than me being up to no good.

Where to in the future?

Whether the system actually works or not remains to be seen, as does whether we will be willing to act on evidence from a machine about someone's intention to commit a future crime. Computer technology can give up new methods but as a society we need to decide what use we will put technology to, and the limits we want to place on it. Perhaps the bigger question here is not "Will it work?" but rather "Will operation hostile intent become a future dream or a nightmare?"

To hear more about the project click here for a BBC radio article on the subject. Audio courtesy of the BBC.