Edmond Locard had a paramount role in the European and worldwide development of criminalistics , the practice of gathering evidence for scientific examination and crime solving.
Locard was born in 1877 in the city of Lyon, France, about 300 miles southeast of Paris. In 1902, He obtained his doctoral degree in medicine. At that point, his interest in science pertaining to the law was already clear, as his thesis was entitled "La médecine légale sous le Grand Roy" (Legal Medicine under the Great King). After receiving his degree, he became the assistant of French medical doctor Alexandre Lacassagne (1844–1921), often referred to as the father of modern forensic medicine, of the University of Lyon. Lacassagne became Locard's mentor. A few years later, Locard decided to study the law, and in 1907, he passed the bar examination. Both a medical doctor and an attorney with a great interest for the study of sciences pertaining to criminal law, Locard had the right educational background and motivation to develop his passion and realize his dream.
In 1908, Locard began traveling the world. He first stopped in Paris, France, to study with French anthropologist Alphonse Bertillon (1853–1914), and to understand the anthropometric system of criminal identification . Locard subsequently visited the police departments of Berlin, Germany, Rome, Italy, and Vienna. His trip took him to the United States where he visited the police departments of New York and Chicago. He finally returned to Lyon in 1910 after a visit to Swiss criminalist Rodolphe Archibald Reiss in Lausanne, Switzerland.
After arriving back in Lyon, Locard's interest in modern and scientific investigation methods dedicated to police work was at its highest. In addition, Lyon was undergoing an increasing number of violent crimes, especially murders. In 1910, Locard was able to convince the Lyon police to establish a laboratory for collecting and examining evidence from crime scenes. They provided him with a few rooms in the attic of the court house in order to set up his laboratory.
In 1912, the laboratory was officially recognized by the Lyon police. Locard then headed the first official police crime laboratory in the world. This laboratory received world recognition and many great criminalists obtained their knowledge and experience under the guidance of Locard in the years that followed. One of these was the Swedish criminalist Harry Söderman (1902–1956), to whom Locard became a mentor.
In 1929 in Lausanne, Switzerland, Locard founded the International Academy of Criminalistics with Swiss criminalist Marc Bischoff, Austrian criminalist Siegfried Trkel, Dutch criminalist C.J. van Ledden Hülsebosch, and German criminalist Georg Popp . Unfortunately, this academy did not survive WWII. Several other police laboratories were created based on the model and influence of Locard. Even after WWII, the French police served as a model to many other countries. Locard was the driving force behind the development of modern scientific and technical police. He died in 1966. Subsequently, a significant decline occurred in criminalistics activity in France.
Locard published more than 40 works in French, English, German, and Spanish. His most famous work, still referenced daily, is the seven volumes of the Traité de criminastique (Treaty of Criminalistics), published between 1931 and 1935. Many of his books represent significant contributions to the field of criminalistics, and forensic scientists often still read his writings. His publications include several works about police investigations that he personally conducted. Locard was also passionate about philately (stamp collecting), and he wrote a few books on this topic.
Locard's contribution to forensic sciences is immense. His most important contribution is the principe de l'échange (principle of exchange). Locard stated "Toute action de l'homme, et a fortiori, l'action violent qu'est un crime, ne peut pas se dérouler sans laisser quelque marque." Translated, it means that any action of an individual, and obviously the violent action constituting a crime, cannot occur without leaving a trace. From this sentence, the whole principle of exchange of traces between two objects entering in contact was established. For example, when a car hits another car, paint from the first car will be deposited on the second one and vice-versa. Similarly, when somebody sits on a chair, fibers from his/her clothing will be deposited on the chair and fibers from the cloth of the chair will be deposited on the person's clothing.
Söderman later wrote of Locard, "He put the analysis of handwriting on a firmer footing, systematized the analysis of the dust in the clothes of suspects, invented a modified method of analyzing blood stains, and invented poroscopy, whereby the pores in the papillary ridges of fingerprints are used as a means of identification."
see also Fingerprint; Handwriting analysis; Locard's exchange principle.