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FINGERPRINTING FACTS

The earliest dated prints of the ridged skin on human hands and feet were made about 4,000 years ago during the pyramid building era in Egypt. In addition, one small portion of palm print, not known to be human, has been found impressed in hardened mud at a 10,000-year old site in Egypt. In ancient Babylon, fingerprints on clay tablets were used for business transactions; in fourteenth-century Persia, many government papers had fingerprints on them; and in Nova Scotia, a prehistoric picture shows a hand with ridge patterns.

It was common practice for the Chinese to use inked fingerprints on official documents, land sales, contracts, loans and acknowledgments of debts. The oldest existing documents so endorsed date from the 3rd century BC, and it was still an effective practice until recent times. Even though it is recorded that the Chinese used their fingerprints to establish identity in courts in litigation over disputed business dealings, researchers fail to agree as to whether the Chinese were fully aware of the uniqueness of a fingerprint or whether the physical contact with documents had some spiritual significance.

Both Nehemiah Grew, M.D. with his 1684 report for the Royal Society of London, and the anatomist Govard Bidloo from Holland in his book on human anatomy in 1685, discussed and illustrated their recognition of the friction ridges and the pores within those ridges. A small number of other academics from various European countries also made anatomical studies of the skin. In 1686 a professor of anatomy, Marcello Malpighi, described the ridges, loops, and spirals of fingerprints. J.C.A. Mayer, in his 1788 book Anatomische Kupfertafeln Nebst Dazu Gehorigen, was the first to state that the “arrangement of skin ridges is never duplicated in two persons." In 1823, another anatomy professor, John Evangelist Purkinje, was the first to describe nine basic fingerprint patterns.

It was not until 1858 that the first practical application of the science was made, when an English administrator in India, Sir William Herschel, commenced placing the inked palm impressions and, later, thumb impressions of some members of the local population on contracts. These prints were used as a form of signature on the documents because of the high level of illiteracy in India and frequent attempts at forgery. Herschel also began fingerprinting all prisoners in jail.


The greatest advances in fingerprint science in the late 19th and early 20th centuries were probably made by Dr. Henry Faulds, a Scottish missionary doctor of the United Presbyterian Church. Faulds first became interested in fingerprints after 1874 while working at the hospital he established in Tsukiji, Tokyo, Japan. After careful experiment and observation, he became convinced that fingerprint patterns did not change, that the fingerprint patterns on the fingers where highly variable and that superficial injury did not alter them, they returned to their former design as the injury healed.

Faulds described the pattern formations on the fingers, referred to "loops" and "whorls"
and stating how good sets of fingerprints may be obtained by the use of "a common slate
or smooth board of any kind, or a sheet of tin, spread over very thinly with printer's ink.
His most important conclusion was that fingerprints do not change and that finger
marks (that is, latent prints) left on objects by bloody or greasy fingers "may
lead to the scientific identification of criminals".



CURIOUS FOOTNOTE: Prior to using fingerprints to identify individuals, a system of measuring bony parts of the body was used. This system was devised in the late 1800s by Alphonse Bertillon, a French anthropologist. Bertillon measured certain bony body parts and then used a formula to come up with a value that would apply to only one person in the world and would not change during that person's lifetime. This technique, named the Bertillon System after its inventor, was accepted as valid for 30 years. In 1903, a bizarre event triggered the end of the Bertillon system. A man by the name of Will West was sent to the federal penitentiary in Leavenworth, Kansas. The problem was that the penitentiary already had an inmate named William West. When photographs of the two men were compared, they were identical. When the authorities used Bertillon measurements, they indicated that both men were the same person. Finally, their fingerprints were compared, proving they were indeed two different individuals. When authorities reviewed prison records and correspondence from the men's families, they discovered that Will West and William West were identical twins. In that same year, the New York state prison system began using fingerprints to identify criminals, and a year later fingerprint identification was started at the Leavenworth penitentiary. Thanks to the West brothers, today we only have to put an inked thumbprint on a piece of paper,
rather than have all of our bony body parts measured.

Fingerprint security: facts about fingerprints
A general overview of how fingerprints are formed, how people leave them behind, and what technologies exist to detect and examine them.

Fingerprints have fascinated people for centuries. They have been used as a method of personal identification (to sign contracts for instance) since ancient times. But where do fingerprints come from? Is it true that they are all different?

Fingerprints are formed before birth, during the development of the hands. Fingerprints aren't actually formed in the skin, but are caused by ridges in the flesh underneath the skin. Their development is partially random, and can be affected by health issues, sometimes distorting them or eliminating them altogether. Genetics plays some part in their formation, but even identical twins (who have identical DNA) have different fingerprints. Fingerprints fall into a set number of patterns, which allows us to catalogue them and perform fingerprint searches more easily. The most common fingerprint pattern is the "Loop", in which the fingerprint ridges start at one side of the finger, loop around at the tip of the finger, and come back to the same side they started on. If you look at your own hands, the chances are you have at least one fingerprint of that type. Over 60% of all fingerprints are loops. Some other common pattern types are Whorls, Arches, and Accidentals. There are many sub-categories as well. And of course, the same ridges cover your palms and the soles of your feet. Both of these have been used to identify people in the past.


Well then, if over 60% of fingerprints have the same pattern, how can they all be different? That is because fingerprints are examined using two different sets of criteria. One way of looking at fingerprints is using their "Class Characteristics". These are general features about the fingerprints, which apply to all fingerprints of that type ("Loop" is a class characteristic). For instance, to say that a car is a "Four-Door Sedan" is to talk about a Class Characteristic of that car. No one would suggest that all four-door sedans are exactly alike. If however, you were to say that the car had a New York State license plate number of X3D4R5, then that is what's called an "Individual Characteristic". No two cars have a New York plate number of X3D 4R5. So fingerprints are identified to a particular person using their individual characteristics, not their class characteristics. If you look very closely at a fingerprint, you will notice that it is made up of ridges on your skin. These ridges aren't always continuous; they stop, split into two, form little pockets (called "lakes") and even appear to cross each other at times. It's these individual features that are different between one fingerprint and the next. By examining and counting these individual features, a fingerprint expert can come to some opinion about whether a particular person made a particular fingerprint. If he or she finds characteristics that don't match, and can't be explained due to pressure distortion or other common problems, then they are obliged to state that the fingerprint did not come from that person. If they find a sufficient number of similarities however, and there are no unexplainable differences, then they may give the investigators and the court their expert opinion that the fingerprints were made by the same person. How many similarities do they need to find? That varies by jurisdiction, from as few as 8 to as many as 16. Ultimately, the fingerprint examiner must state his opinion, and the court must decide how much weight to put on it.


So now that we know what fingerprints are, how do people leave them behind at a crime scene? Since your fingers are covered in skin, they are also covered in skin pores. Skin pores produce oils and sweat, which are distributed on your fingers. When you touch something, those liquids are left on the surface, in the shape of your fingerprints (just like a rubber stamp with ink on it). It's those compounds that can be detected by forensic technicians, using a number of methods. The oily compounds left behind are often detected by good old fingerprint powder, just as you see on any TV detective movie. Like everything however, science has advanced fingerprint powders quite a lot since the early days. Modern fingerprint powders contain various compounds that did not even exist when fingerprint powders were invented (making them far more sensitive), and are usually applied using special soft fiberglass brushes, which do less damage to the fingerprints. When a fingerprint has not yet been detected, it's known as a "latent print" (latent for short). Modern science has found many other ways to detect latents, however. When you touch an object, the chemicals in your sweat may be absorbed into that object (paper is a good example of this), and there are now chemicals which can develop these latents quite nicely. Even paper, which has been soaking wet, can now be successfully examined for fingerprints, using advanced chemicals. The Laser has been a great boon to law enforcement officials as well, due to its ability to detect certain fingerprints. Some types of Lasers cause chemicals in some fingerprints to "fluoresce" or glow, which allows them to be photographed as evidence. There are also dyes that can be sprayed on pieces of evidence to help fingerprints to be more visible to the Laser. The Laser has been extremely useful in obtaining fingerprints from human bodies, a feat that was nearly impossible only a few years ago. Many surfaces, which were difficult to obtain useable fingerprint from in the past, are now routinely examined successfully due to all of these scientific advances.



One of the most common uses of fingerprints is of course, the identification of criminals. ...


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