Fingerprints Lecture 1
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
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
3 Principles of Fingerprints First Principle: A fingerprint is an individual characteristic; no two fingers have yet been found to posses identical ridge characteristics. bsapp.com
Second Principle: A fingerprint will remain unchanged during an individual's lifetime. John Dillinger bsapp.com
Third Principle: Fingerprints have general ridge patterns that permit them to be systematically classified. bsapp.com
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
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.
Modern Fingerprint Analysis Fingerprints Modern Fingerprint Analysis Computer system stores patterns and minutiae of prints AFIS: automated fingerprint identification system
Categorized by pattern and minutiae Fingerprints How are fingerprints analyzed? Categorized by pattern and minutiae
Three Fingerprint Patterns Loops Whorls Arches bsapp.com
Deltas & Cores bsapp.com
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 bsapp.com
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Whorls One or more cores At least two deltas bsapp.com bsapp.com
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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 bsapp.com
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