by Massimo Sideri
Thanks to a database of 60 thousand fingerprints, the system was able to understand when two fingers belonged to the same subject
The uniqueness of fingerprints is, in itself, an axiom: it has never been possible to prove the opposite, so we accept it as given. In fact, for now the empirical evidence has demonstrated it, as they say in American trials, beyond any reasonable doubt. Even in monozygotic twins, who are born from the same egg and therefore have the same DNA, the fingerprints are different, because they are influenced by environmental conditions and epigenetics. Now this axiom has been questioned for the first time and the culprit could only be artificial intelligence. Let’s start by saying that everything is yet to be confirmed. We are at the beginning of a research that has just been published in Science Advances, only after a very complex editorial life precisely because it is a scientific result taken for granted. Technically speaking, we are dealing with clues, not proof.
Similarity between fingers
For now Agatha Christie and a century of detective stories are actually safe: no one has questioned the uniqueness of the prints between different people. But in the study, born by a team led by Gabe Guo, an engineering researcher at Columbia University who had no forensic experience before obtaining this clue, it is hypothesized that there may be a similarity between the prints of different fingers of the same person. individual. Imagine a killer committing a murder leaving a right thumb print. Now imagine the same serial killer committing another murder at another time leaving a left index finger print this time. Until now, forensic science took it for granted that there could be no relationship (which is why in films we see that when fingerprints are taken with ink a card of ten fingers is created).
Uniqueness of the footprints
Guo instead trained an artificial intelligence with a database of 60 thousand fingerprints and found that the machine was able to identify when two fingers belonged to the same subject with an increasing probability (from 77% to 99% in some cases presented in the study). Not sure enough. But from here comes the request for publication in order to continue with training through larger databases. How is it possible that there is a difference between traditional forensic methods and AI? To understand this, it is worth diving for a moment into the fascinating history of fingerprints. The ridges that we all have on our fingertips were first described in 1665 by an Italian, Marcello Malpighi, the father of microscopic observation in anatomy. But we have to get to an article published in Nature in 1880 by Henry Faulds, doctor and missionary in Japan, to read about the uniqueness of fingerprints and their possible use in crime scenes to identify the culprit.
New analysis methods
However, only recently has it been discovered that the mechanism of this uniqueness is very close to that which in nature allows zebras to have a coat with stripes that are never the same between two different animals. A hypothesis that had been anticipated by Alan Turing, the prolific father of artificial intelligence in 1950. Forensic science for decades has been concerned with demonstrating the uniqueness of the footprints of human beings by studying the so-called minutiae, that is, the terminal part of the lines that they create small valleys on our fingers. According to Guo, the trained AI instead changed its methodology, studying more the vortices in the central part of the footprints. For the enthusiastic researcher from Columbia University it would even be proof that AI can find new methods of scientific analysis. But a little early for that. For now it remains a very powerful tool at the service of science.
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January 13, 2024 (changed January 13, 2024 | 2:50 pm)
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