THE RANDLE REPORT

BANG TO RIGHTS

It seems Sherlock Holmes never actually said, ‘Elementary, my dear Watson.’

It’s a case of misattribution, like: ‘Alas, poor Yorrick, I knew him well’, ‘Come up and see me sometime’, ‘Play it again, Sam’, and ‘I believe Iraq has weapons of mass destruction’ – part of the collective memory, but never uttered in fact.

Not long after Sherlock’s time, however, identifying villains became a lot more elementary, thanks to the introduction of fingerprints.

As long as the miscreant’s dabs were taken, and the fingerprints officer wasn’t otherwise influenced in the largely interpretive art of cross-matching by other little hints and suggestions, this was a fair way of putting Chummy where he said he wasn’t.

Bequeathing the method to the police forces of the world, Home Secretary E.R. Henry boasted of its foolproofness on the grounds that ‘everyone’s fingerprints are different’.

Most of us know this as a scientific fact, though it’s never really been proved. Certainly the indications are that it is a high probability – and the chances that the statement applies to the comparatively minimal sample of known criminals is very much higher.

But, even assuming uniqueness, as records increase, differentiation becomes more problematical, with the potential of being overtaken by the inherent margin for error.

As more and more prints were amassed, the forces of the law were forced back again on hunches and hogwash such as psychological profiling, which at least seemed to work on television.

But cometh the hour, cometh the men.

Crick and Watson let the gene genie out of the bottle and the jig was up.

Everyone’s genetic fingerprint is different. It’s a known scientific fact – so you can now be banged up for things you got away with the first time because your finger type fingerprints were smudged or a psychological profiler was looking for Hannibal Lecter.

Genetics is more scientific because it’s got so many billions of little peculiarities that only  computers and algorithms can tell one from the other. ‘Spot the difference’ for the digital age. Perhaps ‘spot the similarity’ is more to the point.

So how many of those billions of peculiarities are found at the average crime scene? A dozen? How stable, how reliable, are the dozen? Pass.

But it’s all very scientific. They scrape up what’s there, set the computer running, and Bob’s your uncle. Or possibly the Avon Lady.

From BLINDED WITH SCIENCE available from The Book Depository