Mark of identity

Fingerprints: murder and the race to uncover the science of identity

Colin Beavan <em>Fourth Estat

In a churchyard near Stoke-on-Trent lies the grave, overgrown with weeds until it was rescued in 1987, of the missionary doctor Henry Faulds. Faulds (1843-1930) died in poverty, his role in the development of fingerprinting largely unrecognised. Colin Beavan places much of the blame for this neglect on the geneticist, eugenicist and biometrician Francis Galton. The missionary doctor's ideas on the scientific and forensic possibilities of fingerprinting had been drawn to Galton's attention by Charles Darwin, and Galton promised to help. If anything, he hindered, and probably not by accident. This at times quite vicious dispute over priority, which involved William J Herschel and other players, is the centrepiece of Beavan's book about the history of the fingerprint and its eventual acceptance worldwide as reliable evidence of identity.

Just as a cross accompanied by "John Smith, his mark" was long accepted in lieu of a signature so, in ancient times, was a thumbprint. Such prints, though personal and a useful proxy in an era of illiteracy, were not thought to be unique. An unclassified and therefore unsearchable collection of prints would be useless beyond the limited initial forensic use of picking up repeat offenders giving false names.

Many, Galton among them, contributed to the development of fingerprinting between Faulds's first (but neglected) publication in Nature in 1880 and a major British trial 25 years later, in which two men were convicted for the murder of an elderly couple in Deptford. The speed with which the UK and US courts accepted this novel form of evidence is surprising given the potential for controversy and some of the statistical arguments that were to attend DNA "fingerprinting" a century later. In France, fingerprinting had to wait for the death of Alphonse Bertillon, whose anthropometric methods then held sway.

Controversy has not disappeared. Last summer, the case against a man charged with burglary was spotlighted on the BBC's Panorama. The only evidence was a thumbprint on a jewellery case. The print belonged to the defendant, but had he handled the box or had the print arrived second-hand, so to speak, from another object? A Metropolitan Police fingerprint expert resigned in order to be free to appear for the defence in the appeal. In the 1905 murder trial, Faulds was willing to appear for the defendants, but was not called. The prosecution had already demolished Herschel's defence opinion because he had offered his services to both sides at the same time. Faulds's motive was honourable; he was worried that the unique individuality of fingerprints had not been established with sufficient rigour for the courts to accept such records - especially, perhaps, when there was no other evidence.

The association of dermatoglyphic patterns (including palmar creases) with certain diseases is no longer a fashionable topic for medical journals, and the main outlet for the subject today is the Fingerprint Society's wonderfully named Fingerprint Whorld. One medical text, referring to our finger ridges and whorls, provides the solemn definition: "A visual record . . . of the cutaneous ridge patterns on the ventral surface of the terminal phalanx."

Beavan's style is far more approachable. His short book blends history, science and anecdote with the testy and arrogant personalities involved, and leaves the reader ashamed that it was left to two Americans to pay for the restoration of Faulds's grave.

David Sharp is a contributing editor of the Lancet