Show us your knees

Historically there have been a range of methods used to uniquely identify people. Fingerprinting has been state of the art when it comes to identifying people for a while now but other methods like voice identification and iris recognition have also been popular. This column has even reported that your body odour is quite distinct. Today DNA testing is all the rage and gets all the headlines but a less flashy method of personal identification, according to a new study, might also be your knees.

Prior to the middle of the 19th century, identity testing essentially came down to, “You look quite a bit like the person who somebody thought they saw near the body, and since nobody likes you very much anyway, we’re going to hang you.” It was a cruel system and, yes, unfair.

Then came the fingerprint. Although fingerprints have been used on documents since the time of the Babylonians, it was in 1858 that Sir William Herschel, a British Administrator in Bengal, made the first practical application of fingerprints for personal identification when he required Indians to place their fingerprints as well as their signatures on contracts. In 1892, Sir Francis Galton published an accurate and in-depth study of fingerprint science, by 1901 the Fingerprint Bureau had been formed at Scotland Yard, and the rest is inky history.

DNA testing is what might be termed the “gold standard” in establishing identity these days but it takes time, and if your aim is crime prevention rather than crime solving then you need some upfront identification strategies. This is where iris identification is useful but contact lenses can subvert that. However, knee-cap scanning could be a useful part of crime prevention in the future according to researchers.

The researchers conducted testing and found that they could identify people by an MRI scan of their knee cap with a 93 per cent accuracy. The advantage of MRI scanning is that it does not have the ionising radiation of X-rays and does not raise the privacy issues of tetraherz scanners which can see beneath a person’s clothing. The problem with MRI technology at the moment is that it is unwieldy. To use it you need to be in a large machine for a long time. However, the researchers say that advances in MRI are happening rapidly and in a few years portable, faster equipment could be able to be part of security systems, as a complement to iris scanning for example.

So in a few years you might be asked to raise your skirt or drop your pants as you enter the airport, and the efficient security staff will explain, “Just need to have a look at your knees, sir (or madam).” If that thought makes you a little nervous, don’t worry: the researchers are confident that knocking knees won’t change your knee-print.