1. Fingerprints
Lecture 1

2. What are fingerprints?
Provide textured surface to grip and hold objects
Formed and arise in skin between epidermis and dermis
Found on fingers, palms, toes and soles of feet
Composed of ridges (hills) and furrows (valleys)
Black = Ridges
White = Valleys

3. Fingerprints
What are fingerprints?
Develop in early embryonic development (by week 17).
Pattern based on genetics, detail somewhat random
Identical twins do not have identical fingerprints

4. 3 Principles of Fingerprints
First Principle: A fingerprint is an individual characteristic; no two fingers have yet been found to posses identical ridge characteristics.
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5. Second Principle: A fingerprint will remain unchanged during an individual's lifetime.
John Dillinger
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6. Third Principle: Fingerprints have general ridge patterns that permit them to be systematically classified.
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7. History of Fingerprints
Criminal identification first done by a system of body measurements called anthropometry.
Bertillon’s anthropometry system used 11 body measurements to identify an individual

8. History of Fingerprints
Henry invented a system for classifying fingerprints.
Allowed fingerprint records to be searched.
Based on all 10 prints, so matching one print would be difficult.

9. Modern Fingerprint Analysis
Fingerprints
Modern Fingerprint Analysis
Computer system stores patterns and minutiae of prints
AFIS: automated fingerprint identification system

10. Categorized by pattern and minutiae
Fingerprints
How are fingerprints analyzed?
Categorized by pattern and minutiae

11. Three Fingerprint Patterns
Loops
Whorls
Arches
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12. Deltas & Cores
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13. Loops
A loop must have one or more ridges that enter from one side of the print, re-curve, and exit from the same side
One Delta & One Core
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15. Whorls
One or more cores
At least two deltas
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17. Arches
An arch is formed by ridges entering from one side of the print, rising slightly and exiting on the opposite side.
No Deltas & No Cores
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