Alphonse Bertillon and the Identity of Criminals

Alphonse Bertillon was a French forensic documentarian who developed or improved upon several methods of identifying criminals and solving crimes. Some of those methods, such as the mug shot, are still in use today, while others, particularly anthropometry, were abandoned over time in favor of more accurate methods. Bertillon is considered by many to be the first forensic expert.

Bertillon’s self-portrait as a mug shot.

Bertillon was a school dropout, and having been trained in no particular field other than that of a soldier, he went to work as a records clerk at the Prefecture of Police in Paris in 1879. The son and brother of statisticians, Bertillon was appalled at the chaos in the criminal offender files. In his spare time, he began to work out a better method. In France at the time, there was a concern over recidivists, or those who committed crimes over and over. Recidivists could draw harsher sentences, but they were difficult to identify, because arrestees were only identified by name and address, and sometimes a picture. But appearance and addresses change, and anyone could lie about their name. With the Paris criminal records system as it was in 1879, if you couldn’t ascertain a suspect’s name, you couldn’t find him in the files, and therefore the rate of recidivism was unknown. Suspected, but unknown.

Anthropometry

An illustration from a book on anthropometry by Alphonse Bertillon.

Bertillon tackled identifying criminals by anthropometry, or the measurements of man. Anthropometry has plenty of uses, in the fields of medicine, anthropology, and engineering, and Bertillon developed another: forensic anthropometry, for the purpose of identifying recidivists and keeping records of criminal offenders. His system, called bertillonage, involved measuring dimensions of the head, face, long bones of the limbs, and other body dimensions. Bertillion entered these measurements into file cards for each arrestee, and sorted them by the offender’s size. A suspected recidivist could be matched by these measurements, and then his name could be cross-referenced to his criminal record.

The major flaw in bertillonage was the assumption that measurements were different for each individual. Bertillon knew, from the Belgian statistician Lambert Quetelet, that the chances of two people being the same height were four to one. Bertillon surmised that the more measurements of different body parts he added, the longer the odds were that two people’s measurements would match. However, several of the measurements he included in his system were directly correlated with an individual’s height.

Still, Bertillion’s system identified recidivists better than any method used previously. In 1884 alone, 241 recidivists were identified when they were rearrested in Paris. The system spread throughout France, and then to other countries. An unsavory side effect was the idea that a “born criminal” could be identified by anthropometry before any crimes were committed, which fed into the eugenics debate.

Sir Francis Galton had his mug shot taken by Bertillon.

Bertillion’s anthropometry measurements were eventually replaced by the more accurate identifier of fingerprints, introduced into forensic science by Sir Francis Galton in the 1880s. But anthropometry wasn’t the only innovation Bertillon made in police record-keeping.

Mug Shots

Bertillon also had a system for incorporating face descriptions into criminal files, which he called “portrait parle.” This involved classifying the shapes of the eyes, nose, mouth, and other features into a coded lexicon that could be used as shorthand. However, the code was extensive and hard to teach to all the police in France, so portrait parle was abandoned in favor of mug shots.

François Bertillon, the photographer’s two-year-old son, mug shot taken in 1893.

Police had been using photography to record criminal appearance since shortly after photography was invented, but it was Alphonse Bertillon who standardized the mug shot into the familiar full-face shot accompanied by a profile view of the same size. The profile view was added because Bertillon saw that the unique shape of the ear is an identifier. His method, adopted in Paris in 1888, was soon used throughout France and in other countries.

Handwriting Analysis

The mug shot of Captain Alfred Dreyfus.

Bertillon’s brief foray into the science of handwriting analysis was a complete failure. He was called to testify in the Dreyfus Affair, in which Captain Alfred Dreyfus was accused of spying on the French military for Germany. The chief evidence against Dreyfus was a document, which he denied writing. There were no competent handwriting experts available, so the famous forensic expert Alphonse Bertillon was summoned, although he had no expertise in handwriting analysis. Bertillon’s initial examination of the document was inconclusive, but he eventually testified that the handwriting was Dreyfus’s, although allegedly Dreyfus had tried to disguise his handwriting as someone else imitating his handwriting. In other words, Bertillon said that Dreyfus was trying to frame someone of framing him. This convoluted logic is attributed to either Bertillon’s confidence that Dreyfus was guilty, or to the French military leaning on the police investigator to find Dreyfus guilty. Later analyses confirmed that Bertillon’s testimony on the handwriting was full of errors. 

Crime Scene Photography

Bertillon was also a proponent of crime scene photography. Photographing murder victims was important for capturing the ability to identify them before their bodies decayed or were disposed of. He developed a standardized technique of photographing a murder victim from above, in order to record the body’s position in situ before investigators disturbed the scene. Forensic measurements could be taken from the images any time afterward.

Although not all of Bertillon’s techniques panned out, he brought a sense of discipline to record keeping and crime investigation that opened doors for further developments in criminal justice.

This post was inspired by a picture found in an old issue of The Annals of Improbable Research, in which a cat is observing Bertillon at work.