1. INTRODUCTION TO FINGERPRINTING
INTRO TO FINGERPRINTING
Classification
Authors: Veon and O’Boyle 2007 1

2. INTRO TO FINGERPRINTING
LOOP
LOOPS
Comes in
Recurves
Goes back out same side
Usually curving around a delta
INTRO TO FINGERPRINTING 2

3. INTRO TO FINGERPRINTING
ARCH
ARCH
In one side
Rises
Falls
Goes out the other side
INTRO TO FINGERPRINTING 3

4. INTRO TO FINGERPRINTING
WHORL
WHORL
Ridge recurves around 2 deltas
INTRO TO FINGERPRINTING 4

5. In Depth Classifying 8-TYPES
Looking in depth, there are really 8 basic patterns.
INTRO TO FINGERPRINTING 5

6. INTRO TO FINGERPRINTING
LOOP-the ridges flow inward and then recurve in the direction of the origin. --A single delta type divergence must be present in front of the recurving ridges
Radial Loop-Ridges flow from the recurve toward the radius or thumb side of the hand (approximately 5% of all fingerprint patterns)
Ulnar Loop-Friction ridges flow from and recurve toward the ulna or little finger side of the hand, (Approximately 60% of all fingerprint patterns)“PU”
LOOP-In Depth
INTRO TO FINGERPRINTING
Radial Loop
Ulnar Loop 6

7. INTRO TO FINGERPRINTING
ARCH-In Depth
ARCH-Ridges enter on one side of the impression and tend to flow out the other side with a rise in the center
Plain Arch-Ridges enter, wave or rise and exit smoothly
INTRO TO FINGERPRINTING
Plain Arch
Tented Arch-Ridges in the center thrust upward to give an appearance similar to a tent. Inside angle is smaller than 90 degrees
Both types of arches comprise about 6% of all fingerprint patterns
Tented Arch 7

8. INTRO TO FINGERPRINTING
WHORL-In Depth
WHORL-At least two delta type divergences are present with recurving ridges in front of each. (whorls comprise approximately 29% of all fingerprint patterns)
Plain Whorl-One or more ridges form a complete revolution around the center (2 deltas)
INTRO TO FINGERPRINTING
Plain Whorl
Central Pocket Loop Whorl- Some ridges form a loop pattern which recurves and surrounds a central whorl (1 delta)
Central Pocket
Loop Whorl 8

9. INTRO TO FINGERPRINTING
Additional Types
Double Loop-Two separate loops are present, which sometimes surround each other. Sometimes called Double Loop Whorl (ying / yang)
INTRO TO FINGERPRINTING
Double Loop
Accidental-Any pattern
which does not conform to
any of the previous patterns
Accidental 9

10. FINGERPRINT INDIVIDUALIZATION
BEYOND THE PATTERN
BEYOND THE PATTERN
FINGERPRINT INDIVIDUALIZATION

11. BEYOND THE PATTERN RIDGE ENDING BIFURCATION DOT or ISLAND
LAKE or ENCLOSURE
INDEPENDENT RIDGE
SPUR
BRIDGE or CROSSOVER 11

12. BIFURCATION
BEYOND THE PATTERN 12

13. SPUR
BEYOND THE PATTERN 13

14. RIDGE ENDING
BEYOND THE PATTERN 14

15. BRIDGE or
CROSSOVER
BEYOND THE PATTERN 15

16. LAKE
or ENCLOSURE
BEYOND THE PATTERN 16

17. DOT or ISLAND
BEYOND THE PATTERN
INDEPENDENT
RIDGE 17

18. What next... BEYOND THE PATTERN
Just the presence of these minutia does not individualize a print
It is the exact type of minutia as well as the minutia location that individualizes a print
NO TWO PRINTS HAVE EVER BEEN FOUND TO HAVE THE SAME MINUTIA IN THE SAME PLACE
Therefore, you can conclude if you are comparing two prints, and they do have the same markings in the same place you must be looking at the same print
BEYOND THE PATTERN 18

19. So how many correlations prove a match?
It was in 1918 when Edmond Locard wrote that if 12 points (Galton's Details) were the same between two fingerprints, it would suffice as a positive identification. This is where the often quoted (12 points) originated.
Be aware though, there is "NO" required number of points necessary for an identification.
Some countries have set their own standards which do include a minimum number of points, but not in the United States.
Most agencies intentionally vary the number of correlations to avoid a standard or pattern
BEYOND THE PATTERN 19