The Henry Classification System is a long-standing method by which fingerprints are sorted by physiological characteristics. Developed by Sir Edward Henry in the late 1800s for criminal investigations in British India, it was the basis of modern day AFIS classification methods up until the1990s. In recent years, the Henry Classification System has generally been replaced by ridge flow classification approaches. Sir William Herschel found that fingerprints remain unchanged over time. He also found that each individual’s fingerprints are unique to that person.
He instituted a system by which fingerprints were used to sign documents, identification, and a means to authenticate transactions. However, a system in which records of individuals would be filed and searched was not yet invented. “Dr. Henry Faulds was the first European to publish the notion of scientific use of fingerprints in the identification of criminals. In 1892, Sir Francis Galton published his highly influential book, Finger Prints in which he described his classification system that include three main fingerprint patterns – loops, whorls and arches. ” (International Biometric Group, 2003).
In 1896 Sir Edward Henry, then the Inspector General of the Bengal Police in India, intrigued by the use of fingerprints for identification of criminals contacted Sir Galton. The two men corresponded regularly and in 1896, Sir Henry ordered the collection of prisoner’s fingerprints along with their anthropometric measurements. By gathering both pieces of information he expanded on Sir Galton’s classification system. A commission was later established to compare Anthropometry to the Henry Classification System to determine which system of identification was better.
The commission found that using fingerprints was the better approach. The Henry Classification System allows for logical categorization of ten-print fingerprint records into primary groupings based on fingerprint pattern types. This system reduces the effort necessary to search large numbers of fingerprint records by classifying fingerprint records according to gross physiological characteristics. Subsequent searches (manual or automated) utilizing granular characteristics such as minutiae are greatly simplified.
The Henry Classification System assigns each finger a number according to the order in which is it located in the hand, beginning with the right thumb as number 1 and ending with the left pinky as number 10. The system also assigns a numerical value to fingers that contain a whorl pattern; fingers 1 and 2 each have a value of 16, fingers 3 and 4 have a value of 8, and so on, with the final two fingers having a value of 1. Fingers with a non-whorl pattern, such as an arch or loop pattern, have a value of zero. (Harling 1996).
When AFIS technology (Automated Fingerprint Identification System) was first introduced it was meant to be used to expedite the manual searching of recordings thus reducing the time it takes to make a match from possibly months to mere hours. AFIS began to classify fingerprints according to the distance between the core and delta, minutiae locations, and pattern type; the later being based on the Henry Classification System. “Presently, there are some forensic AFIS solutions (e. g. state and local) that still employ a Henry Classification System based manual fingerprint filing. However, other than for legacy systems, the Henry Classification System is not essential for automated systems.