FINGERPRINTS

History of fingerprints 1892 – Galton wrote book “Finger Prints” Anatomy of prints Determined that no two prints were the same A person’s prints remain unchanged 1901 – US adopted fingerprint system 1924 – fingerprint collection established at FBI 1999 US v. Byron C. Mitchell Case argued that fingerprints are not unique. Judge ruled that prints are unique and permanent.

1st Principle of Fingerprints No two people have identical fingerprints 64 billion possibilities Individuality of fingerprints determined by RIDGE CHARACTERISTICS (minutiae) Identify number and relative location of characteristics Approximately 150 characteristics per print About 15 needed for court admissibility

2ND PRINCIPLE OF FINGERPRINTS Fingerprints remain unchanged during an individual’s lifetime Fingerprints are formed from friction skin ridges on the palm side of the fingers and thumbs

2ND PRINCIPLE OF FINGERPRINTS Fingerprints are formed from papillary skin ridges on the palm side of the fingers and thumbs.

2nd PRINCIPLE OF FINGERPRINTS Epidermis – outer skin Dermis – inner skin Papilla – boundary between two skin layers Develops on the fetus and remains unchanged Determines form and pattern of ridges

2nd Principle of Fingerprints: Pores – discharge and deposit perspiration Once the finger touches a surface the perspiration is transferred onto that surface, leaving an impression of the finger’s ridge pattern Latent Fingerprint – prints that are invisible to the naked eye the naked eye

2nd PRINCIPLE OF FINGERPRINTS Can one change his/her fingerprints? Injuries that reach to the papilla (1-2 mm deep) leave permanent scars John Dillinger – attempted to obliterate fingerprints by pouring acid on them. (Ironically, this made his prints more distinguishable.)

3rd Principle of fingerprints Cores and Deltas

3rd Principle of fingerprints Loops Ridge lines enter from one side of the pattern and curve around to exit from the same side of the pattern One delta 60 - 65% of the population

3rd Principle of Fingerprints Whorls Ridge patterns that are generally rounded or circular in shape and have two deltas. 30-35 % of the population has whorls

3rd principle of fingerprints Arches Ridge lines enter from one side and flow out the other side 5 % of the population No delta