The Henry System

Before computers, fingerprint databases were held by police using a card filing system. The system converts the ridge patters on all ten fingers into letter classifications

Developed in 1900, this system was adopted by Scotland Yard in 1901

4 Classifications

Loop

Whorl

Arch

Composite i.e accidentals (subtype to whorls)

Maximum number of classifications = 1024

Plain

Tented

Radial

Ulnar

Plain

Central Pocket Loop

Double Loop

Accidential

Cores and Deltas

Delta - Triangular area, analogous to a river delta

Core - The approx centre of the pattern

Fingerprints are the impressions of friction ridge - plain arch

Ridges flow from one side of the pattern to the other with a rise or wave in the centre

Has a gentle upward curve

Tented Arch

Has a well defined angle or central upthrust

Regarded as transitional pattern between arch and loop

More complex

Loop Patterns - Radial

Loop subtypes are based on the direction of the pattern

Radial loops travels towards the thumbs

Ulnar - travels towards little finger

Whorl - Has two deltas like a bulleye target, own core and Delta