1. Fingerprint Classification

2. Classifying Prints Why classify prints? To add order to chaos – like a library organizing books by author or subject matter. Fingerprints are only useful if they can be searched quickly for a match. How are prints classified (grouped)? By arches, loops, whorls – each person has a different number of these types of patterns Everyone has these, but HOW people have them is unique

3. Arches Ridgelines that rise in the center to create a wave- like pattern Types: Plain, Tented 5% of all pattern types

4. Loops One or more ridges that double back on themselves. Types: Radial, Ulnar – Categorized by how they flow – Radial: Flow down, toward the radius (thumb side) – Left Loop – Ulnar: Flow toward the ulna (little finger) – Right Loop 60% of pattern types

5. Loops (Right Loop – coming from the right)(Left Loop – coming from the left)

6. Whorls “Whirlpools” of ridgelines Types: – Plain: concentric circles (“bulls eye”) – Central pocket: Loop with whorl at the end – Double: two loops that collide – S shape pattern – Accidental: whorls that are different from each other and are irregular 35% of pattern types

7. Whorls

8. Individual Ridge Characteristics

9. Henry Classification System Sir Edward Henry (British police) - 1899 Prints are assigned a score based on where whorls show up within a ten-finger set of prints. Total score is used to narrow down matches into all sets with same scores (1,024 different groups). Totals Right Index 16 Right Ring 8 Left Thumb 4 Left Middle 2 Left Little 1 Right Thumb 16 Right Middle 8 Right Little 4 Left Index 2 Left Ring 1

10. AFIS Automated Fingerprint Identification System Scanning and digital encoding of fingerprints Searches 500,000 prints per second! Once a match is found, an agent hand-checks the file(s) Problem: Many AFIS systems exist are not compatible

11. Types of fingerprints Patent Plastic Latent

12. Powdering Prints

13. Chemistry with Prints Cyanoacrylate Vapor Iodine Fuming Ninhydrin Silver nitrate

14. Digital Fingerprinting