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Refers to an impression left by the friction ridges of a human finger.
Moisture and grease on a finger result in fingerprints on surfaces such as glass or metal.
Deliberate impressions of fingerprints can be obtained by ink or other substances transf2242ed from the peaks of friction ridges on the skin to a smooth surface such as paper.
Normally contain impressions from the pad on the last joint of fingers and thumbs.
Human fingerprints are nearly unique, difficult to alter, and durable over the life of an individual.
They may be employed to identify individuals who wish to conceal their identity, or to identify people who are incapacitated or deceased and thus unable to identify themselves, as in the aftermath of a natural disaster.
Matching of two fingerprints is among the most widely used and most reliable biometric techniques.
A friction ridge is the raised portion of the epidermis on the fingers and toes, the palm or the sole of the foot.
These epidermal ridges amplify vibrations triggered, when fingertips brush across an uneven surface, better transmitting the signals to sensory nerves involved in fine texture perception.
These ridges assist in gripping rough surfaces and may improve surface contact in wet conditions.
The uniqueness of a fingerprint can be indicated by the overall pattern of ridges and valleys, or the logical ridge dicontinuities known as minutiae.
A fingerprint classification system groups fingerprints according to their characteristics.
Such a classification helps in the matching of a fingerprint against a large database of fingerprints.
There are a number of. Classification systems: in the Henry classification system there are three basic fingerprint patterns-loop, whorl, and arch which constitutes 65%, 30-35%, and 5% of all fingerprints, respectively.
More complex classification systems exist that include patterns into plain arches or tented arches, and into loops that may be radial or ulnar, and whorls.
Fingerprint identification,is known as dactyloscopy or hand print identification.
It is the process of comparing two instances of friction ridge skin impressions from human fingers or toes, or even the palm of the hand or sole of the foot, to determine whether these impressions could have come from the same individual.
No two finger or palm prints are ever exactly alike in every detail.
Even identical twins do not have identical fingerprints.
When two impressions recorded immediately after each other from the same hand may be slightly different.
Fingerprint identification, utilize techniques, rules to determine whether two friction ridge impressions are likely to have originated from the same finger or palm.
A recording of friction ridges is usually made with black printer’s ink rolled across a contrasting white background, typically a white card.
Friction ridges can also be recorded digitally, usually on a glass plate, with a technique called Live Scan.
The three basic patterns of fingerprint ridges are the arch, loop, and whorl:
arch: The ridges enter from one side of the finger, rise in the center forming an arc, and then exit the other side of the finger.
loop: The ridges enter from one side of a finger, form a curve, and then exit on that same side.
whorl: Ridges form circularly around a central point on the finger.
A latent print refers to a chance recording of friction ridges deposited on the surface of an object or a wall.
Latent prints are invisible to the naked eye, and are often fragmented, and require the use of chemical methods, powder, or alternative light sources to be made clear.
When friction ridges are added to a surface to make a print, any material on the friction ridges including perspiration, oil, grease, ink, or blood, will be transf2242ed to the surface.
Factors affecting the quality of friction ridge impressions include: Pliability of the skin, pressure applied, slippage, surface material and its roughness.
Every instance of friction ridge deposition is unique.
Dermatoglyphics is the science of fingerprints
Fingerprints deliberately collected whether for purposes of enrollment in a system or when under arrest for a suspected criminal offense is known as exemplar prints.
For criminal arrests prints will normally include one print taken from each finger and impressions of each thumb.
A partial fingerprint lifted from a surface, is called a latent fringerprint.
Moisture and grease on fingers result in latent fingerprints on surfaces, and to be clearly visible their detection may require chemical development through powder dusting, the spraying of ninhydrin, iodine fuming, or soaking in silver nitrate.
Different techniques are used for porous surfaces, such as paper, and nonporous surfaces, such as glass, metal or plastic.
Latent fingerprints on nonporousp surfaces require the dusting with fine powder and a brush, followed by the application of transparent tape to lift the latent fingerprint off the surface.
The impression of the same fingerprint changes every time the finger is placed on the sensor plate, increasing the complexity to match fingerprints.
Non-contact or touchless 3D fingerprint scanners acquire detailed 3D information by a digital approach to the analog process of pressing or rolling the finger.
Fingerprints of a dead person may be obtained during an autopsy.
Fingerprints are typically formed from the aqueous-based secretions of the eccrine glands of the fingers and palms with additional material from sebaceous glands, particularly from the forehead.
The forehead is contaminated results from the common human behaviors of touching the face and hair.
Latent fingerprints consist of a substantial proportion of water with small traces of amino acids and chlorides mixed with a fatty, sebaceous component which contains a number of fatty acids and triglycerides.
The fingerprint contains secretions, skin oils and dead cells, and contains residues of various chemicals and their metabolites present in the body.
Fingerprints of tobacco smokers contain traces of cotinine, and nicotine itself.
Testing coffee drinkers, cannabis smokers, and users of various other drugs can be accomplished.
Fingerprints identifications has also been valuable in the aftermath of natural disasters and anthropogenic hazards.
Gloves themselves can leave prints that are as unique as human fingerprints.
A very rare medical condition, adermatoglyphia, is characterized by the absence of fingerprints, and is caused by the improper expression of the protein SMARCAD1.
The chemotherapy medication capecitabine may cause the loss of fingerprints.
Aging decreases the elasticity of skin , with ridges increasingly thick, and the height between the top of the ridge and the bottom of the furrow narrower making it more difficult to obtain fingerprints.
Fingerprints can be erased permanently by burning the fingertips, using acids and plastic surgery.
Minutiae features are considered the most discriminating and reliable feature of a fingerprint.
The most widely used minutiae features used for automated fingerprint verification are the ridge ending and the ridge bifurcation.
Family members often share the same general fingerprint patterns, suggesting that these patterns are inherited.
A fingerprint sensor is an electronic device that captures a digital image of the fingerprint pattern.
Optical scanners create a visual image of the fingerprint using a digital camera.
Ultrasound fingerprint scanners use high frequency sound waves to penetrate the epidermal layer of the skin, and thermal scanners sense the temperature differences on the contact surface, in between fingerprint ridges and valleys.