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Fingerprints

Fingerprints. Recording and classifying prints Rolling inked prints Loops, whorls, arches, ridge characteristics Primary identification number Lifting prints Black, white, and fluorescent powder Chemicals — ninhydrin, iodine, silver nitrate, cyanoacrylate Other types of prints

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Fingerprints

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  1. Fingerprints Recording and classifying prints • Rolling inked prints • Loops, whorls, arches, ridge characteristics • Primary identification number Lifting prints • Black, white, and fluorescent powder • Chemicals—ninhydrin, iodine, silver nitrate, cyanoacrylate Other types of prints • Palm, lip, teeth, eye, ear, voice, shoeprints, and footprints

  2. Fundamental Principles of Fingerprints • A fingerprint is an individual characteristic. • A fingerprint remains unchanged during an individual’s lifetime. • Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.

  3. When do fingerprints form? • Ridges form in early embryonic development (3rd or 4th month) • remain constant throughout life.

  4. What determines fingerprint pattern and minutiae? • DNA: Genes • Environmental forces: pressures within the womb and contact with the amniotic fluid

  5. What do the genes control? • The tissue underlying the first few layers of skin is controlled by genes. • This tissue forms a unique pattern in the skin layer – Dermal Papillae • Environment has more to do with fingerprints than genes!!

  6. John Dillinger – couldn’t change fingerprints with acid Can only be altered by deep scarring of dermal layer (2-3mm).

  7. History of Fingerprinting • Used in Ancient China as far back as 3 thousand years ago to sign documents.

  8. William Herschel (1858) • India - English civil servant required natives to sign • contracts with the imprint of right hand

  9. Henry Fauld (1870’s) • Became the first person to solve a crime using fingerprints. • Matched the fingerprints found on a cup at a robbery in Tokyo with those of a servant. • First to suggest fingerprinting as the primary means of identification.

  10. Francis Galton (1892) • Fingerprints do not change as you age • No two are exactly the same. • Odds of two fingerprints being the same were 1 in 64 billion. • Published 1st book on Fingerprinting • Coined terms: loops, arches, and whorls.

  11. Sir Edward Henry (1897) • Developed a System to file fingerprints

  12. Fingerprinting in the US • NY was the 1st state to use fingerprints – 1901 • Became the official system of criminal identification in the U.S. in 1924 at the formation of the F.B.I.

  13. US vs. Mitchell (1999) • Challenged the individuality of fingerprints • Court ruled Human friction ridges are unique & permanent

  14. Famous Cases Peter Griffiths – • killed a 3 year old. • Mass fingerprinting was done to find the killer.

  15. Dactyloscopy: The study of Fingerprints History from 1850 to 1900 • William Herschel—required Indians to put their fingerprints on contracts, and used fingerprints as a means of identifying prisoners • Henry Faulds—claimed that fingerprints did not change over time and that they could be classified for identification • Alphonse Bertillon—proposed body measurements as a means of identification; termed anthropometry • Francis Galton—developed a primary classification scheme based on loops, arches, and whorls • Edward Richard Henry—in collaboration with Galton, instituted a numerical classification system • Juan Vucetich—developed a fingerprint classification system based on Galton’s that is used in Spanish-speaking countries

  16. Fingerprinting • Height – Fingerprinting surface should be 39 inches from floor • Clean fingers with alcohol swab • The individual should stand to the right and rear of the person taking the fingerprints in front of the card

  17. Fingerprinting Procedure • Thumbs rolled toward the center of the body • Fingers rolled away from the center of the body.

  18. Roll each finger in the correct space taking care to lift each finger up and away after rolling, to avoid smudging.

  19. Rolled impressions • The upper ten impressions are taken individually Rolling Prints

  20. Flat Impressions- Taken simultaneously without rolling, at a 45oangle and then the thumbs.

  21. What can go wrong?

  22. Ridge Characteristics Minutiae - characteristics of ridge pattern • Ridge ending • Island or short ridge • Bridge • Eye or enclosure • Delta • Bifurcation or fork • Dot • Spur • Double bifurcation • Trifurcation

  23. Ridge Characteristics

  24. Crossover Core Bifurcation (fork) Ridge ending Scar Island Delta Pore

  25. Furcations • Bifurcation • Trifurcation • Double bifurcation • Opposed bifurcation

  26. Endings • Ridge Ending • Opposed Bifurcation Ridge Ending

  27. Hook, Dot, Island, & Lake • Island (Short Ridge) • Dot • Lake (enclosure) • Hook

  28. Bridge & Ridge Crossings • Bridge • Ridge Crossing

  29. Fingerprint Minutiae

  30. Arch • An arch has friction ridges that enter on one side of the finger and cross to the other side while rising upward in the middle. They do NOT have type lines, deltas, or cores. • Types • Plain • Tented

  31. Loop • A loop must have one or more ridges entering and exiting from the same side. Loops must have one delta. • Types • Radial—opens toward the thumb • Ulnar—opens toward the “pinky” (little finger) • Which type of loop is this, if it is on the right hand? Left hand?

  32. Whorl • A plain or central pocket whorl has at least one ridge that makes a complete circuit. • A double loop is made of two loops. An accidental is a pattern not covered by other categories. • Whorls have at least two deltas and a core. • Types • Plain • Central pocket • Double loop • Accidental

  33. Loop Whorl Arch

  34. Percentages in the Population • Loop – 65% • Whorls – 30%-35% • Arches – 5%

  35. Core • Top of the innermost recurving ridge. • Center of the pattern

  36. Type Lines • Diverging ridges that go above & below the loop

  37. Delta • The point of divergence of the type lines

  38. Loop Pattern • One or more ridges entering and exiting from the same side it began. • Must have one delta.

  39. Types of Loops • Radial--opens towards thumb • Ulnar--opens towards pinky

  40. Whorl • Have type lines and a minimum of 2 deltas • Types • Plain • Central Pocket • Double Loop • Accidental

  41. Plain & Central Pocket loop • Both have at least one ridge that makes a complete circuit (spiral). CENTRAL POCKET LOOP - Line drawn between the two deltas doesn’t touch a spiral ridge PLAIN - Line drawn between the two deltas touches a spiral ridge

  42. Double loop • Two loops combined • s-shaped

  43. Accidental • Has 2 or more patterns (not including the plain arch)

  44. Arches • Ridges enter on one side and cross to the other side while rising upward in the middle. • No type lines, deltas, or cores.

  45. Types • Tented sharp center rise Plain

  46. What is the fingerprint pattern? Plain arch Tented arch Plain whorl Loop (r or u)

  47. Which Loop is it? radial ulnar

  48. The Henry System (1899) • Classification system using all 10 fingers. Based on identifying the patterns of each finger. • 1,024 labels are created. • Still used today.

  49. The fingerprint record is filed under its label • To locate a record, only 1 / 1,024th of the entire collection must be examined

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