How Many Fingerprints Does a Person D...

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Author Message   Webservant Posted on Wednesday, June 08, 2005 - 07:12 am:        3,847, no make that 3,849... no, 3,928 if they don't wash their hands often. J Just kidding... the variables for the numbers you seek are tremendous. It would also be nearly impossible to measure "how many times an individual may leave their fingerprint on different objects in a day or week." In your photographic exhibit, I recommend that you include a close-up image of pores along the peaks of fingerprint ridges (similar to the peaks of mountain ridges). The pores resemble miniature bird baths. Those tiny bird baths are constantly replenished with eccrine gland secretions (98 to 99% water) that are deposited on each surface touched... deposited in a pattern conforming to the peaks of the ridges bearing those tiny bird baths. How many prints will be deposited, and of those deposited, how many will be identifiable, is subject to factors that are impossible to predict and which vary widely from person to person. Eccrine gland secretions are influenced by factors such as the following: Temperature (hot weather makes you sweat more); Diet (gustatorial sweating... remember how your forehead starts dripping while eating spicy food?); Mental excitement/stress (that is why polygraph examiners put those galvanic skin response electrodes on your fingers - to measure eccrine gland secretions and the resulting fluctuation in electrical resistance); Physical exercise (the amount of sweat during exercise will be impacted by the temperature and relative humidity). Think of fingerprints as being somewhat similar to pre-inked (self-replenishing) rubber stamps. Imagine yourself going through a day or week using those ink stamps to touch everything. Sometimes the stamp may not leave a legible impression because there was insufficient time between "touches" for the ink to recoat the surface. Sometimes the surface touched may be too rough to record a legible impression. Sometimes the stamp may be sliding/smearing the impression during the touching. Sometimes someone else's stamp may obliterate your stamp on a doorknob. To make the concept of name stamps even more similar to fingerprints, imagine that instead of blue, red or some other color of ink, that your stamps are depositing water-based invisible ink that dries within minutes after touching a surface and can only be seen with an ultra-violet light. There could be thousands of stamp impressions on surfaces "touched" during a day/week. How could you count all of the impressions or even know if you shined the UV light in all the places necessary to find them? And like fingerprints, your stamps will sometimes pick-up contaminates such as oil, dirt, paint, or blood... and will deposit varying amounts of those contaminates in a number of impressions. Real latent finger and palm prints are more difficult to detect (simply using any type of light source without other chemical processing is not going to find many of them). Providing a statistic as to how many identifiable fingerprints a person deposits in a single day would cost a fortune for the forensic processing alone, not to mention the hundreds of thousands of dollars in damage done to walls, equipment, doors, cars, etc., due to chemical processing to detect and harvest all the identifiable latent prints. Suffice it to say that the number of prints an individual may deposit in a day or week is between zero (for some persons in a catatonic state, paralyzed or unconscious) to many thousands.   Daniel Aziz Posted on Tuesday, June 07, 2005 - 02:57 pm:        Hi, I am setting up a photography exhibition based on fingerprints and I am wondering if anyone knows where I can seek information about surveys carried out on fingerprints? What I need, is any approximations about how many times an individual may leave their fingerprint on different objects in a day or week?