Fingerprint

From Freepedia

This article is about human fingerprints. See also Fingerprint (disambiguation).

A fingerprint is an imprint made by the pattern of ridges on the pad of a human finger. These ridges are commonly believed to provide traction for grasping objects.

Fingerprints are unique, with no two fingers having the exact same friction ridge characteristics. Also, fingerprints do not change significantly with age. If a finger is damaged, it will normally heal in such a way that the fingerprint is restored. Because of these characteristics, a person's fingerprint can be used as a method to identify human individuals.

Fingerprints (or more commonly, footprints) are sometimes used to identify infants, though this practice is not as common as it used to be, especially with DNA identification becoming more commonplace.

Image:Fingerprintonfinger.JPG

Fingerprints are an early example of biometrics, the science of identifying individuals by their physical characteristics. There is no clear date at which fingerprinting was first used, some examples being from prehistory. However, some significant modern dates are as follows.

1880: Dr. Henry Faulds published his first paper on the subject in the scientific journal Nature in 1880. Returning to Britain in 1886, he offered the concept to the Metropolitan Police in London but was dismissed.
1892: Sir Francis Galton published a detailed statistical model of fingerprint analysis and identification and encouraged its use in forensic science in his book Finger Prints.
1892: Juan Vucetich, an Argentine police officer who had been studying Galton pattern types for a year, made the first criminal fingerprint identification. He successfully proved guilty Francisca Rojas, who had murdered her two sons, finding her bloody fingerprint in the crime scene.
1901: Sir Edward Henry devised the Henry Classification System used in England and Wales.
1902: Dr. Henry P. DeForrest used fingerprinting in the New York Civil Service.

Recently the American Federal Bureau of Investigation adopted the D9/7 wavelet-based system for efficient storage of fingerprint data, developed by Ingrid Daubechies. The FBI manages a fingerprint database called IAFIS, which currently holds the fingerprints of over one hundred and ninety-eight million subjects.

In the 2000s, electronic fingerprint readers have been introduced for security applications such as identification of computer users (log-in authentication). However, early devices have been discovered to be vulnerable to quite simple methods of deception, such as fake fingerprints cast in gels.

There is some controversy over the uniqueness of fingerprints. Even those who accept their uniqueness sometimes argue that the techniques used to compare fingerprints are fallible.

Friciton ridge identification (or Dactylography, a term mainly used in the US) is established through the agreement of friction ridge characteristics in sequence, having sufficient uniqueness to establish individuality.

When a person touches something with his fingers, there will usually be an visible or invisible residue left on the touched surface. The residue is patterned as a copy of the person's fingerprint and can be collected for visual study and comparison. Traditionally, finely ground powders of chalk or coal have been used to make the fingerprint clearly visible. The powder adheres to the fingerprint residue but not the surrounding surface. Sometimes the prints are invisible, in which case they are called "latent fingerprints". There are chemical techniques such as cyanoacrylate fuming and ninhydrin spray that can help make them visible.

Fingerprints collected at a crime scene can be used in forensic science to identify suspects.

Fingerprint analysis emerged in the late 19th century, when it was the first method in forensic science for unique identification. As a result of its early success, it acquired a mystique of infallibility. It has only recently been subjected to systematic analysis by investigators from outside the field.

Fingerprint examiners have certainly disagreed with one another: the case of Shirley McKie was a notable case involving fingerprints. Experienced fingerprint experts have also made mistakes, one of the most recent and newsworthy erroneous identifications was made by the FBI linking one Brandon Mayfield to the Madrid bombings!

William West

The most famous case in the history of fingerprinting occurred in the late 19th century when a man was spotted in the incoming prisoner line at the U.S. Penitentiary in Leavenworth, Kansas by a guard who "knew" him and had just seen him already in the prison population. Upon examination, the incoming prisoner claimed to be named Will West, while the (not escaped) existing prisoner was named William West. According to their Bertillon measurements, they were essentially indistinguishable. As they were not twins, the Bertillon system came into some question. However, their fingerprints were different, and fingerprint identification received a significant boost in credibility.

Classifying fingerprints

There are three basic fingerprint patterns: Arch, Loop and Whorl. There are more complex classification systems that further break down the pattern to plain arches or tented arches. Loops may be radial or ulnar. Whorls also have smaller classifications. However, the five most commonly used are: whorl, radial loop, ulnar loop, arch and tented arch.