All About Fingerprints
Whorls: circular or spiral in shape
Arches: mound-like contour (tented arches have a spike appearance)
Loops: concentric hairpin or staple-shaped ridges
Radial: loops toward the thumb
Ulnar: loops slope toward the little finger side of the hand
Loops make up about 65 percent of the total fingerprint patterns. Whorls account for about 30 percent. Arches and tented arches are the most rare, together constituting only about 5 percent of fingerprints. The ulnar loop is the most common pattern of all fingerprints.
A latent fingerprint is one that is left of the scene of a crime (as opposed to one collected with ink). The ridge structure must be reproduced from on an object in where it was left in sweat, oily secretions, or other substances present on the culprit's fingers. Most latent prints are invisible to the naked eye and must made visible, then preserved, analyzed, and compared. Fingerprints are brushed with special powders containing chalk or lampblack and other agents. They can then be photographed or lifted with tape.
Fingerprints are impressions made by the papillary ridges on the ends our fingers. Because these ridges are unique to every human being and do not change with growth or age, they make an ideal form of identification. The practice of using fingerprints as identification is called dactyloscopy. It is an indispensable tool for modern law enforcement. This article is all about fingerprints and how they are used for identification and investigation. Kids will love to learn about fingerprints.
What is the Purpose of Your Fingerprint?
Papillary ridges stick out from the skin of the fingertips. They remain unaffected by superficial burns, abrasions, or cuts and their original pattern continues with each new layer of skin that grows. These ridges allow you to grasp objects. Without the friction they provide, items would routinely slip from your hands. Their use as identification is just an added benefit.
A Short History of Fingerprints
While any ridged area of the hand or foot is unique and may be used as identification, finger impressions are preferred because they are easy to capture and classify. Fingerprint ridges form basic shapes of arches, loops, and whorls. These were identified by Sir Francis Galton and Sir Edward R. Henry in the first fingerprint classification system, known as the Galton-Henry System in 1900.
The Galton-Henry system was widely adopted law-enforcement agencies in the English-speaking world and continues today as the most widely used method of fingerprint classification. Juan Vucetich devised an alternative system known as the Dactiloscopía Comparada, which is still used in most Spanish-speaking countries.
Fingerprints are classified in a three-way process: by the shapes and contours of individual patterns, by noting the finger positions of the pattern types, and by relative size, determined by counting the ridges in loops and by tracing the ridges in whorls. The information obtained in this way is incorporated in a concise formula, which is known as the individual's fingerprint classification.
Eight Patterns of Fingerprints Recognized by the FBI:
- radial loop
- ulnar loop
- double loop
- central pocket loop
- plain arch
- tented arch
- plain whorl
All About Fingerprints
Fingerprint Classification Project