1. FINGERPRINTS

2. 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.

3. 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

4. 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

5. 2ND PRINCIPLE OF FINGERPRINTS
Fingerprints are formed from papillary skin ridges on the palm side of the fingers and thumbs.

6. 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

7. 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

8. 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.)

9. 3rd Principle of fingerprints
Cores and Deltas

10. 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
% of the population

11. 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

12. 3rd principle of fingerprints
Arches
Ridge lines enter from one side and flow out the other side
5 % of the population
No delta