1.29.14 Forensic Fingerprint Science.docx

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Environmental Toxicology
ETX 20
Kanthaswamy, Sreetharan

Forensic Fingerprint Science Biological basis? Fingerprint science is bas used ed on a number of related hard sciences (it is an applied science) Your fingerprints never change throughout life Grew (1684) phubished first paper that observed ridfe structure on fingers Bidloo (1685) etc. Bertillion (classification) Galton (ridge characteristics, 1 book –plagerized from Darwin) Vucetic/Henry used fingerprints for crime Locard established rules and could identify really easily,’ How do you make fingerprints Fingerprints are unique, they are randomly formed using volar pads (bubbles on fingers, determines shape of patterns, inherited because they are based upon bone structure th Formed at 10 weeks, completely done by 25 week. Create loops or whorls or arches. Caused by the mechanics of stress Primary ridge is the higher part (accommodates sweat ducts, secondary ridge is the lower bit Remains constant forever (or until you star your fingers What is the scientific basis? Fingerprints are permanent (basal layer—provides nutrients to build more skin cells) Ridge formations are unique It is statistically and biologically impossible for duplication In over 100 years of use which includes automation, no two persons were ever found to have the same identical relationship of ridge features. Some areas of lesser details can be duplicated. Not even identical twins have same fingerprints—come get close fut never Even clones have different fingerprints Galtan characteristics = points of identification FRICTION RIDGE IDENTIFICATION • “The individualization of an impression is established by finding agreement of corresponding individual characteristics of such number and significance, as to preclude the possibility of their having occurred by mere coincidence, and establishing that there are no differences that cannot be accounted for” • Harold Tuthill Individualization: Principles and Procedures in Criminalistics The Scientific Principle Of The Fingerprint Identification Process • ANALYSIS • COMPARISON • EVALUATION – In order to establish a positive identification, a sufficient number of ridge characteristics must be in the approximate same position, and the exact same unit relationship – Unit relationship is the same number of intervening ridges between one ridge characteristic and another, in both impressions • VERIFICATION Evaluation sees latent vs inked copy—try to find characters prior to viewing sample (thus sufficient uniqueness of ridge detail to conclude that the two impressions are from the same people What is sufficient? Clearer image, less reuired Used to have 12 point rule—1972 FBI you can identify in less than 12 but 12 will always be sufficient Locard’s Tripartite Rule • In 1914, Dr. Locard published his conclusions of the fingerprint identification and the criteria that should be used to assure reliability based upon statistical analysis study. His study showed the following tripartite rule summarized as follows • If more than 12 concurring points are present and the fingerprint is sharp, the certainty of identity is beyond debate. • If 8 to 12 concurring points are involved, then the case is borderline and the certainty of identity will depend on: • the sharpness of the fingerprints; • the rarity of its type; • the presence of the center of the figure [core] and the triangle [delta] in the exploitable part of the print; • the presence of pores [poroscopy]; • the perfect and obvious identity regarding the width of the papillary ridges and valleys, the direction of the lines, and the angular value of the bifurcations [ridgeology / edgeoscopy]. • If a limited number of characteristic points are present, the fingerprints cannot provide certainty for an identification, but only a presumption proportional to the number of points available and their clarity (inconclusive result) International Assoc. for Identification (IAI) • In 1973 and 1974 the IAI attempted to establish a fingerprint standard for conclusions (determined that there is no standard) • The Ne’urim (in 1995) declaration was a new citation to supplement the 1973 IAI statement • Up to the 1990’s quantification was still being utilized by most – “Because fingerprint science is objective and exact, conclusions reached ar
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