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Fingerprinting

Fingerprinting. Prehistoric. In ancient Babylon, fingerprints were used on clay tablets for business transactions. In ancient China, thumb prints were found on clay seals. July of 1858.

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Fingerprinting

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  1. Fingerprinting

  2. Prehistoric • In ancient Babylon, fingerprints were used on clay tablets for business transactions. • In ancient China, thumb prints were found on clay seals.

  3. July of 1858 • Sir William Herschel, Chief Magistrate of the Hooghly district in Jungipoor, India, first used fingerprints on native contracts.

  4. 1882: Anthropometry • Bertillon

  5. Francis Galton (1888): loops, arches and whorls Sir Edward Richard Henry (1900): "The Classification and Use of Fingerprints."

  6. Principles of Fingerprints. 1. An individual characteristic. 2. Remain unchanged during an individuals lifetime. 3. General ridge patterns permit fingerprints to be systematically classified.

  7. First Principle • Individuality is determined by the ridge characteristics (also known as minutiae) notthe general pattern. • Record identity, number and relative location of minutiae that impart individuality.

  8. Fingerprint Ridge Characteristics

  9. Matching ridge characteristics between a crime-scene print and an inked impression of a suspect’s finger.

  10. Second Principle • Fingerprint will remain unchanged during an individual’s lifetime. • Dermal papillae determines the ridges and pattern on the surface of the skin.

  11. Perspiration and oils are secreted onto the skin’s surface. • Visible latent fingerprints are the impression of the oils/sweat onto another surface.

  12. Third Principle • 3 classes based on general pattern Loops Whorls Arches (60-65%) (30-35%) (5%)

  13. General Fingerprint Patterns

  14. Loop pattern. Core - the center of the loop. Delta is the area of the pattern where there is a triangulation or a dividing of the ridges.

  15. Arch patterns. The Arch pattern has no delta or core. However, it must be fully recorded so that its individual characteristics can be readily distinguished.

  16. Whorl patterns - 4 subtypes A Whorl pattern will have two or more deltas. All deltas and the areas between them must be recorded.

  17. Inked prints

  18. Fingerprint cards

  19. Classification of Fingerprints. • Henry System R.IndexR.RingL.ThumbL.MiddleL.Little R.Thumb R.Middle R.Little L.Index L.Ring Whorl pattern on: any finger of first pair value = 16 ………………second pair value = 8 ………………third pair value = 4 ………………fourth pair value = 2 ………………last pair value = 1 Loop or arch on any finger value = 0 (after all ten fingers are totaled add 1 to both the numerator and the denominator)

  20. Automated Fingerprint Identification System (AFIS) • Automatically scans the print  digital minutiae. • Image is stored as digitally recorded geometric pattern. • AFIS can search a set of 10 prints against a file of 500,000 in 0.08 seconds.

  21. AFIS printout

  22. Types of Fingerprints. • Visible prints • Plastic prints • Latent prints Found on newly painted object, wax from candles or sealants, in the gum on envelopes and stamps, on substances that melt easily or soften when they are held in the hand e.g. chocolate.

  23. Visualizing Prints. • Locate first! Reflected Ultraviolet Imaging System (RUVIS) • Developing depends on the surface.

  24. Developing Prints • Fingerprint powders e.g. gray powder, black powder, fluorescent powder, magnetic powder. • Chemical Methods e.g. iodine fuming, ninhydrin, physical developer, superglue, fluorescence.

  25. Chemical Methods • Iodine fuming • Ninhydrin stain • Physical developer

  26. Chemical Methods cont. • Superglue/cryoacrylate ester fuming • Fluorescence

  27. Visualization of Latent prints.

  28. Digital Imaging • Can enhance fingerprints for the most accurate and comprehensive analysis. • Image  digital file  pixels • Each pixel is assigned a number according to its intensity (0-225). • Pixel number altered to achieve max. resolution.

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