New biometric measures: Birth marks, scars, and tatoos

Published 20 June 2008

Michigan State researcher develops a system that could allow police to identify individuals by matching marks on their body with those stored in a computer database

You have kids contemplating going to the local tatoo parlor to have some art (if this is the right term) carved on their skin? You may want to tell them this: Michigan State University researchers have created a system that could allow police to identify individuals by matching marks on their body with those stored in a computer database. Personal identity is usually established by police using passports, licenses, or personal identification numbers, but these are easily forged, lost, or stolen. What is more, these types of credentials are neither sufficiently reliable nor secure. A better means to recognize people is to use biometric systems that can identify them from their fingerprints, iris or face. Anil Jain, Michigan State University’s distinguished professor of computer science and engineering is taking biometric recognition one step further by adding scar, mark, and tattoo recognition capabilities. Called “Tattoo-ID,” the system Jain has been working on includes an annotated database containing images of scars, marks, and tattoos provided by the police.

In use, the system matches a suspect or a victim’s distinguishing marks against the database and determines the suspect’s identity with very high accuracy. While a scar, mark, or tattoo cannot uniquely identify a person, it can help the authorities narrow down the list of potential identities. It can also indicate membership in a gang, social and religious group or military unit. Jain said that if an officer arrests a person who does not have any identifying documents and uses an alias, but has a tattoo belonging to a known gang, the tattoo gives additional evidence to identify which group the person belongs to. For recognizing the deceased, the system could be extremely useful. “A body can decompose quickly, particularly in adverse climate conditions, making it difficult to perform face or fingerprint identification,” Jain said. “But because tattoo pigments are deeply embedded in the skin, even severe skin burns often do not destroy tattoos.” Jain’s research team is continuing its research to improve the performance of the tattoo image matching system in collaboration with the Michigan State Police Identification Section, which has provided him access to its large tattoo image database.