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