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“Fingerprints cannot lie, but liars can make fingerprints” -Unknown.

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Presentation on theme: "“Fingerprints cannot lie, but liars can make fingerprints” -Unknown."— Presentation transcript:

1 “Fingerprints cannot lie, but liars can make fingerprints” -Unknown

2  First systematic attempt at personal identification devised by Bertillon in 1883  Three parts:  Anthropometry  Portrait parlé  photographs

3  11 measurements  Detailed descriptions  Disease  Accidents  Deformities  Scars, tattoos, moles, warts, etc.

4  Evidence in early China  William Herschel (India) used handprints for legal documents

5  It’s basically an impression of the pattern of ridges on the last joint of a person’s finger  They are so useful for ID because:  The ridges are unique and characteristic  They are consistent over a person’s lifetime  There is a systematic classification  Are humans the only ones?  Why do we have them?

6  Individuality of a print is not determined by general shape or pattern, but in a careful study of the minutiae (the ridge characteristics)

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8  Remember that skin is layers of cells  Nearest the surface – epidermis  Inner skin – dermis  Boundary of cells separating the dermis and epidermis – shape is made up of dermal papillae – that determines the form and pattern of the ridges  Each ridge populated by single row of pores that are openings for sweat glands – perspiration (along with oils) is transferred onto surfaces when touched

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10  All fingerprints divided into three classes based on general pattern:  loops (60-65%)  whorls (30-35%)  arches (~5%)

11  ulnar loop – ridges open towards pinky finger  radial loop – ridges open towards thumb  core – center of the pattern

12 Ulnar loop (on left, will flow out of right) Radial loop (on left hand, will flow out of the left)

13  must have at least two deltas and a core  four types  plain  central pocket  double  accidental

14 plain- two deltas with curving ridges central pocket – notice different deltas/different ridges

15 double whorl accidental – follows whorl rules, but may include other pattern types

16  simplest to spot  ridges enter one side and exit the opposite plain arch – no upthrust in middle of print, ridges flow smoothly from one side to another tented arch – has upthrust greater than 45 degrees in middle of print


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