Fingerprint Images Forensics Mr Foster LOOP WHORL ARCH

Fingerprint Images Forensics Mr. Foster

LOOP WHORL ARCH

Calculating Primary Henry Classification Each Finger is given a point value

Calculate your Primary Henry Classification Assign the number of points for each finger that has a whorl and substitute into the equation: right left index ring thumb middle little 16 + 8 + 4 + 2 + 1 right left thumb middle little index ring 16 + 8 +1 + 4 + 2 + = +1 1 Only add the number if you have a whorl on the finger!

Frequency of Fingerprint Patterns Secondary Henry Classification Loops Whorls Arches 65% 30% 5%

There are more than 3 pattern classifications. Right hand Ulnar Right hand Radial

thumb side Pinky side

Frequency of Fingerprint Patterns Secondary Henry Classification Loops Whorls Arches 65% 30% 5% More specific %’s for categories of each pattern type Ulnar Radial Plain Other Plain Tented 60% 5% 20% 10% 4% 1%

Fingerprint Lab and Probability Secondary Henry Classification 2. What would happen to your probabilities if you incorporated the more specific %’s?

Minutiae Or Triradius

Activity #2 Identify 1 -15

Activity #3 - look at the handout and identify prints that came from the same finger.

KEY

Key to Fingerprint Matching Worksheet • A = G = S This one is interesting; there are three separate impressions of the same finger with some very unique features. • B = no match • C = no match • D = no match • E=T • F=J • H=R • I = no match • K=O • L = no match • M=P • N=Q