INTRODUCTION TO FINGERPRINTING

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INTRODUCTION TO FINGERPRINTING
INTRO TO FINGERPRINTING

• Classification

Authors Veon and OBoyle 2007
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LOOP

• LOOPS
• Comes in
• Recurves
• Goes back out same side
• Usually curving around a delta

INTRO TO FINGERPRINTING
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ARCH

• ARCH
• In one side
• Rises
• Falls
• Goes out the other side

INTRO TO FINGERPRINTING
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WHORL

• WHORL
• Ridge recurves around 2 deltas

INTRO TO FINGERPRINTING
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In Depth Classifying8-TYPES

• Looking in depth, there are really 8 basic
  patterns.

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LOOP-In Depth

• 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

INTRO TO FINGERPRINTING
Radial Loop
Ulnar Loop
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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
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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
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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
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BEYOND THE PATTERN
BEYOND THE PATTERN
FINGERPRINT INDIVIDUALIZATION
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RIDGE ENDING
BIFURCATION
DOT or ISLAND
LAKE or ENCLOSURE
BEYOND THE PATTERN
INDEPENDENT RIDGE
SPUR
BRIDGE or CROSSOVER
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BIFURCATION
BEYOND THE PATTERN
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SPUR
BEYOND THE PATTERN
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RIDGE ENDING
BEYOND THE PATTERN
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BRIDGE or CROSSOVER
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LAKE or ENCLOSURE
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DOT or ISLAND
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INDEPENDENT RIDGE
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What next...

• 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

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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
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