Why do people's fingerprints are unique and will not be repeated?

It is true that everyone's fingerprints are unique. So far, scientists have found 150 kinds of feature points (according to the ridge characteristics of fingerprints) for comparison and recognition, but how many feature points do two fingerprints have to match to judge that they belong to the same person? This is a problem. Britain generally requires 16, Australia 12, and India only needs 8. There is no unified national standard in the United States and Canada, but the US Federal Bureau of Investigation stipulates 12. According to the Criminal Investigation Technology Section of Beijing West Railway Station Branch, there are only eight China. (Some people who study forensic medicine said that China required 13 in theory, but actually seven were enough. )

In fact, there is no essential difference in the number of feature points, because no conclusive scientific research can give a recognized conclusion and how many to set. So this makes some people doubt whether fingerprint identification is really reliable.

For example, a law professor at the University of Virginia in the United States suggested that the statement that "no two people's fingerprints are exactly the same" is not rigorous enough, because until now, some two people's fingerprints have not been found to be exactly the same, and it cannot be inferred that there are absolutely no two people with identical fingerprints in the world. Moreover, because there is no recognized standard to define whether two fingerprints match, when faced with incomplete or fuzzy fingerprints, it is even more unreliable to identify prisoners according to fingerprints.

Although this statement is extreme, there are still many defenders of fingerprint identification at present. After all, this objection is a bit too metaphysical. Practice has proved that it is convenient and effective to judge criminals by fingerprints. Moreover, modern fingerprint extraction technology has become a highly sophisticated and complicated program, and its reliability is naturally greatly improved.