Biometric technology has become an accepted and normalised presence in our everyday lives. From fingerprint scanners on our smartphones to saying “my voice is my password” to your bank’s automated phone system, biometrics is everywhere. But it hasn’t always been that way. It has taken many decades for biometric identification to become sufficiently accurate and reliable for day-to-day use.
Biometrics in the ancient world
The term ‘biometric’ comes from the Greek ‘bio’, meaning ‘life’, and ‘metric’, meaning ‘measure’. It refers to the use of unique human physiological features for the purposes of identification and verification. For hundreds, if not thousands of years, humans have understood that facial features, handprints, fingerprints, and voices are unique to individuals. In the modern era, research and technology have allowed us to add iris patterns and DNA profiles to this list.
The first recorded use of fingerprints and handprints for identification purposes is from 1858 in India. However, there is evidence from around the world that the uniqueness of these features has been utilised for far longer. In ancient Babylon almost 4000 years ago, contracts were written into clay tablets. To prevent forgery and falsification, the parties involved in the contract pressed their fingerprint into the clay1. In China, fingerprints were used for identification during the Tang Dynasty (618-906 AD). Ink prints and clay seals were used as a form of signature on legal documents2.
In the Western world, Sir William James Herschel is generally credited with the first use of fingerprints for identification. In 1858, he was working for the India Civil Service in Jungipoor. While setting up a contract with a local man for the supply of road-making materials, Herschel needed a way to hold the man to the contract’s terms. Herschel asked him to put his handprint on the document3.
Later, as Herschel’s interest in hand and fingerprints advanced, he realised that they could also be used for identification purposes. While in post as the Magistrate of Hooghly from 1877, Herschel collected fingerprints from retired people in the area. This was intended to ensure that pension payments were paid only to those entitled to them. During this same time, Herschel began taking fingerprints from criminals4. Identifying criminals from their fingerprints prevented them from hiring impostors to take on their prison sentences in their place.
Herschel was a pioneer of fingerprint identification. However, he only ever used it for administrative purposes. The later work of Francis Galton and Edward Henry used Herschel’s ideas and converted them into a method for catching criminals.
Bertillonage and fighting crime
Alphonse Bertillon became engrossed in the identification of criminals while working for the police in Paris in the 1880s. His long-standing interest in anthropology helped him to devise the system of measurements that would become known as Bertillonage. The system consisted of measuring certain parts of the human body. These included the width of the skull, the length of the foot, and the length of the left middle finger. The measurements were recorded on special cardboard forms and filed systematically in one of 243 categories. Eye colour and hair colour was also incorporated into the filing system. The combinations of all the recorded factors resulted in just over 1,700 separate groups into which individuals were sorted.
In an average database of 5,000 people sorted according to the Bertillonage system, each category would contain just over 20 people. With eye and hair colour also taken into account, there would be fewer than three people in each group. It was therefore relatively fast and easy to compare the measurement card of a recently captured suspect to the correct database category. If a match was found, the crime was added to the suspect’s card5.
Bertillonage was officially adopted by the police force in Paris in 1882. The system spread rapidly to other police forces throughout the world. In 1887, it was introduced in the United States at Illinois State Penitentiary6. In 1889, the Buenos Aires police inaugurated their own anthropometry department based on Bertillon’s methods7.
Shortfalls of the Bertillonage system
Although Bertillon’s methods revolutionised criminal identification and acted as a catalyst for research into more modern methods, Bertillonage quickly fell out of use. In the USA, where the population was much greater and databases could contain more than 50,000 Bertillon measurement cards, the system was unwieldy. As the database grew, the amount of time it took to compare the cards increased from a few minutes to several hours8.
At the same time, there were significant problems with inaccuracy of measurements. The examiners taking the measurements were not always competent or experienced enough, and mistakes were frequent. In addition, criminal suspects caught in their teen or early adult years proved a problem. If they were examined at the point of their capture, the measurements might change by the time they reached their full adulthood.
In the 1890s, fingerprint classification was superseding Bertillonage in the UK. The work of Francis Galton and Edward Henry laid the foundations for the crime-fighting fingerprinting methods that are still in use today.
Sir Francis Galton was a hugely multi-talented scientist with interests in a wide range of subjects. Over his life, he was a cartographer, statistician, geographer, meteorologist, explorer, and anthropologist. Coming from a wealthy family, Galton was able to fund his research into whatever topic took his fancy.
Galton was the first to embark on a scientific study of fingerprints. He collected a huge sample of over 8,000 sets of prints, and analysed them in detail. In studying the characteristics that make up human fingerprints, Galton was able to prove, statistically, the uniqueness of each individual’s prints9. The unique features of fingertips are still commonly referred to as Galton’s details10.
The Henry System
Sir Edward Henry was born in 1850 and raised in London. In 1873, he joined the Indian Civil Service at Fort William in Bengal. By 1891, he had risen to the role of Inspector-General of Police in Bengal. By this stage, Henry had already been in contact with Francis Galton. They exchanged letters on the subject of fingerprinting for criminal identification. Henry was using Bertillonage anthropometry in the Bengal police department, and was looking to either replace or supplement that method with systematic fingerprinting11.
Henry began collecting prisoners’ fingerprints as well as their anthropometric data. Azizul Haque, one of the workers in Henry’s team, developed a method of organising and storing fingerprints. The system had to allow police to search the fingerprint database quickly and efficiently, in order to avoid repeating the issues posed by Bertillonage. It eventually became known as the Henry Classification system. Fingerprint patterns were divided into four types. Arches, loops, whorls, and composites were recorded, analysed, and stored for future usage. The terminology and methods used by Henry have become the primary global fingerprint identification standard.
Pioneering work in Buenos Aires
The earliest case of fingerprints being used for criminal identification comes from Argentina in 1892. The Buenos Aires police department, having already been an early adopter of Bertillonage, had invested in a ground-breaking Center for Dactyloscopy. Juan Vucetich, the Croatian-born police analyst who ran the Center, was a pioneer in forensic investigation.
Vucetich became involved in the case of Francisca Rojas, a woman who has found wounded alongside her two children, who later died from their injuries. Rojas claimed that they had been attacked by a neighbour. However, the neighbour denied any wrongdoing and provided an alibi. Upon examining the crime scene, the local police inspector found a bloody fingerprint and called on Vucetich for help. Vucetich found a match between the bloody fingerprint and those of Francisca Rojas. Rojas immediately admitted that she had inflicted her own injuries upon herself and fatally hurt the children12.
Catching criminals in London
It was ten years later before fingerprints were used to convict a criminal in the UK. After his success in Bengal, Sir Edward Henry returned to London in 1901. There, he established the Metropolitan Police Fingerprint Bureau. The Bureau collected the fingerprints of suspects by dipping them in ink and printing them onto paper.
Originally, the goal of the Bureau was to prevent criminals from lying about prior convictions. However, it wasn’t long before the fingerprint database began to play a pivotal role in identifying and convicting criminals. In 1902, Harry Jackson broke into a home in London and stole some billiard balls13. Unfortunately for him, the windowsill where he had entered the house had been freshly painted. The print of his left thumb that he had left in the paint was photographed and compared to the Bureau’s database. Harry Jackson was identified, arrested, and his fingerprints recorded once again. The new set matched the crime scene fingerprint, and Jackson was sentenced to seven years in prison, the first British conviction based on fingerprint evidence14.
The 20th Century biometric boom
Biometric technology exploded in the 20th Century. Particularly from the 1960s onwards, advancements in technology and research made biometrics a field of serious potential. Facial recognition, iris patterning, acoustic speech analysis, and the discovery of DNA expanded the horizons of biometric research. There have been far too many developments to cover in this blog post alone – another one will be coming soon!
William Herschel, Francis Galton, and Edward Henry could not possibly have imagined our world today, where everybody carries a device fitted with an instant and automatic fingerprint scanner in their pocket. Their work laid the foundations for the development of a huge and exciting industry of its own. At CDVI, we’re proud to play our part.