Posts Tagged ‘Edmond Locard’

The French Connection of Sherlock Holmes

February 25, 2011

by E. J. Wagner

This article first appeared in Canadian Holmes, The Journal of the Bootmakers of Toronto (for subscription information see their web site) – Volume 33 Number 2, Winter 2010/2011 – the illustrations here were included with the article in that issue and are reproduced here with the permission of the publisher.

E. J. Wagner is an American crime historian, lecturer and the author of the Edgar®-winning The Science of Sherlock Holmes.

In 1910, the criminal courts of Lyon were housed in the old Palais de Justice, which has a cornerstone laid in 1835. It was an enormous and impressive building, boasting an elegant entrance and a sweeping exterior staircase that ran the down to the Saône river.

A much less salubrious door in the rear of the building led to cramped jail cells, rank with the smell of mold and despair. Next to the cells lay cluttered rooms bursting with massive police files, which included exacting dossiers on anyone who had ever suffered the misfortune of attracting the attention of the French police.

Just off the file room, a creaking staircase twisted up three stories to the pair of attic rooms newly assigned to the experimental cause of forensic investigation. These were equipped with a microscope, a spectroscope, a collection of basic chemicals, and a Bunsen burner. Presiding over the Lilliputian space was a slim man whose aquiline nose and hooded eyes lent him the keen expression of a benign hawk.

His name was Edmond Locard. Within two years his small attic rooms would become world famous as the formidable Police Laboratory of Lyon, and he would earn the sobriquet of “The Sherlock Holmes of France.”

Born in 1877, Locard was a child of ten when The Great Detective made his initial appearance in A Study in Scarlet, and the two scientific investigators, one fictional and one very real, developed and matured simultaneously, Holmes often providing the source of the Frenchman’s inspiration. (Holmes, of course, had French forbears, and perhaps this made Locard find him particularly congenial.)

As eclectic in his interests as Holmes was, but more traditional in his pursuits of them, Locard acquired formal degrees in both medicine and law. He served an apprenticeship with the great forensic specialist Lacassagne, worked with the criminologist Bertillon in Paris, and traveled the world studying police investigation before he undertook the directorship of the tiny Lyon laboratory. Passionate and knowledgeable about music and theater, he wrote criticism of both for Lyon newspapers. A generous man, he repeatedly gave full credit to his fictional mentor.

In his 1929 paper on “The Analysis of Dust Traces,” Locard wrote:

I hold that a police expert, or an examining magistrate, would not find it a waste of his time to read Doyle’s novels. For, in the adventures of Sherlock Holmes, the detective is repeatedly asked to diagnose the origin of a speck of mud, which is nothing but moist dust. The presence of a spot on a shoe or pair of trousers immediately made known to Holmes the particular quarter of London from which his visitor had come, or the road he had traveled in the suburbs. A spot of clay and chalk originated in Horsham; a peculiar reddish bit of mud could be found nowhere but at the entrance to the post office in Wigmore Street.

And urging his readers to seriously study Holmes, Locard added:

One might profitably re-read . . . the stories entitled: A Study in Scarlet, The Five Orange Pips, and The Sign of Four. Elsewhere Holmes insists upon the interest and fascination to be found in collecting tobacco ashes . . . (The Boscombe Valley Mystery.) On the latter point one should again read The Sign of the Four, and also The Resident Patient.

Sharing Holmes’ regard for the importance of dust, Locard examined specimens gathered from unusual sources—including human ears, eyebrows and nostrils.

In one experiment, he was able to accurately discern the occupations of 92 of 100 individuals merely by careful analysis of dust gathered from their eyebrows—flour in the baker’s, soot in the chimney sweep’s, iron filings in the locksmith’s. (There is no record of what, if anything, was discovered in the eyebrows of an accountant.)

One hundred years ago forensic science was still a generalist’s field—and Locard, like Holmes, vigorously researched and wrote extensively about fingerprints, trace evidence, document examination, tobacco, seeds, insects, and other detritus found at crime scenes. His passion for experimentation led him to burn his own fingertips to determine if fingerprints can be permanently removed this way.  He painfully discovered they could not.

He was responsible for the incarceration of countless unpleasant persons—forgers, murderers, sexually repressed purveyors of poison pen letters, and enterprising thieves, including a burgling monkey with a penchant for jewelry.

Like Mr. Holmes, Locard was intensely interested in cryptology, and in September of 1914, much to the relief of the French Command he helped to break the German cipher, preventing an early French defeat.

In Locard’s seven volume study of forensic science, Traité de Criminalistique, he made the statement which has influenced generations of forensic investigators: “Il est impossible au malfaiteur d’agir avec l’intensité que suppose l’action criminelle sans laisser des traces de son passage” (It is impossible for a criminal to act considering the intensity of the crime, without leaving a trace).

This is often referred to as “Locard’s Exchange Principle” and sometimes given as “Every Contact Leaves Trace.” This abbreviated version, while true enough, neglects the emotional sensitivity of Locard’s observation—the idea that the criminal will be undone by his own tension and excitement.

One fine example of this is a celebrated train murder of 1864 in London, in which Franz Müller, having killed a fellow passenger, departed the scene carrying the victim’s hat, which he had mistakenly exchanged for his own easily identifiable one, left behind with the body.

A recent example is provided by the terrorist who, in May 2010, left a car loaded with explosives in New York City’s very busy Times Square. Evidently the “emotion of the moment” caused him to forget all his keys in the vehicle, leaving him unable to access either his getaway car, parked eight blocks away, or his domicile. As he also left his hazard lights on, the attention of the authorities was prompt. Locard, no doubt, would have smiled.

(How the tyro terrorist managed the feat of locating not one, but two free parking places in mid-Manhattan, remains a puzzlement.)

Edmond Locard died in 1966, but his work remains relevant and vital today, and tied forever to insights and adventures of Mr. Holmes. In May 2009, Dr. Locard was posthumously awarded a decoration in honor of his contributions to science.  It was given by the Société Sherlock Holmes de France.

Editor’s Note: E.J. Wagner’s website can be found at
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