Fingerprint - biological identity

A criminal in the United States used to cut pieces of skin on his fingers and put them on other fingers, thinking he would escape. But the police found him by cutting pictures of these fingerprints and trying to put the pieces together as a puzzle.

Finger skin folds in each person are governed by many genes. The number of wrinkles and their morphology will not change throughout life. So far, fingerprints are still the universal but precise mark to identify people of security agencies.

Johannes E.Purkinje Professor (Photo: police)

At a glance, the man's finger and the finger of the other person didn't seem much different. But actually, each person's fingerprints have their own unique characteristics.

Since the 15th century, Chinese people have used finger fingerprints to point to evidence in papers. In Europe later. In 1823, Professor Johannes E.Purkinje mentioned fingerprint classification. By 1901, the fingerprint appraisal department was actually formed and widely applied in many countries, becoming the main method in the form of learning.

Fingerprints have many very specific features: the end of the fingerprint line, its turn, buttons, ' ledge ' or ' island '. Whether or not these characteristics and the relative position between them allows building a fingerprint pattern and determining a correlation coefficient between them.

In addition, people also classified the fingerprints into big families: leaning to the left, leaning to the right . Over 60% of people have a standard structure: toward the right for the fingers in the left hand . Fingerprint experts say that the probability of two people having the same fingerprint strokes is less than one billion.

Today when the age of identity card is reached, everyone must roll their fingers to leave fingerprints in the police archives. Fingerprint identification is an important standard of criminal inspection. So now, even the new thieves will find ways to leave fingerprints on the scene.

Imprints go through life

Fingerprints are present at the age of 5-6 months of the fetus, growing in years and until death remains unchanged. There are criminals who have used abrasive stone to lose fingerprints, but to no avail, new skin rises with full imprint of old fingerprints.

There was a special case: In 1990, Miami police (USA) arrested a suspected drug trafficker. He cut the pieces of skin on his fingers and put them on other fingers. He thought, so the police could not match him to previous crimes. An FBI specialist cut the pictures of these fingerprints and tried to join the pieces together as people play a puzzle. He recovered many of his original fingerprint samples. The police compared and found them to be similar to the fingerprint of a fugitive being wanted in an important drug case.

Modern techniques with fingerprints

Humans are " forever ", always changing: changing residence, born, growing and dying; So how should the authorities determine fingerprints with the shortest time?

Many countries have applied electronic computers to identify fingerprints. The machine is classified by fingerprint items, analyzed and selected specific characteristics, compared with fingerprint data in archives and only in seconds can identify the fingerprints of any individual .

Currently, the application of fingerprints has many new advances. One of them is taking fingerprints with ferromagnetic filings. According to traditional techniques, people sprinkle powder on suspicious surfaces with fingerprints. The powder adheres to the fat layer left by the hand, the excess powder will be wiped clean and eventually fingerprints can help police find the object of investigation.

FG75 device to get Startek fingerprint (Photo: startek)

However, scanning the excess powder can obscure fingerprints that are very faint. On the other hand, for rough or porous surfaces, the classic technique is less effective. Therefore, British scientists have studied a fingerprint-taking technique that gives very good results even with the faintest fingerprints. Instead of using powder, they use iron filings with glue to attach to the surface, the excess iron filings are removed by magnets and leave fingerprints without damaging. The researchers found that iron filings with a width of 25 microns would give the sharpest image.

Scientists also successfully built a very special ' fingerprint key '. People encode all types of employee fingerprints and put them into the memory of electronic computers. Only that hand was put in, the door opened. In some industrialized countries, this particular key is most commonly used in banks, important filing cabinets, customs offices and high-end hotels.

Startek, Taiwan, is one of the leading firms that has built such equipment. Startek equipment is about the same size as a shoe box. When placing your finger on the small window, the tiny semiconductor video camera in the device scans the surface of the finger 30 times / second, then selects the clearest picture. Next, the special electronic system will capture detailed information, curves, spiral . of fingerprints. This code is then transferred to the computer, to match the original fingerprint template already in memory.

In the United States, people are studying a type of fingerprint recognition pistol, only its owner can use it. The electronic locking system of the gun is built on the basis of identifying the fingerprint of the owner. Sandia Creast Laboratory in the US completed this gun. Legalists hoped that in the future, that kind of gun would prevent murderers. They cannot use weapons to steal from others.

Doctor Vu Nguyen Khiet