Friction Ridge Skin
The aim of this chapter is to provide a brief summary of the basic elements of
friction ridge skin morphogenesis and their relationship to friction ridge skin variability.
More extensive accounts for latent fingerprint examiners can be found in
Ashbaugh (1999b), Wertheim and Maceo (2002), and Bush (2002). These contributions,
with their associated references, constitute the essential material required to
gain an understanding of the biological basis for friction ridge pattern variability.
They complement and extend the work undertaken by earlier pioneers such as Wilder
and Wentworth (1932) and Cummins and Midlo (1961).
Two cornerstones to the use of fingerprints as a mean of personal identification
are the permanence (persistency or durability) and the uniqueness of friction ridge
skin. Both of these foundations have been extensively challenged and confirmed
through 100 years of fingerprint identification practice, but their scientific basis lies
within biological research.
Unless examiners have a good understanding of friction ridge skin morphogenesis
(the biological development of form), the basic tenet for individuality is often
resolved by using standard, shallow statements such as “nature never repeats itself.”
We cannot accept that the justification for individualization essentially revolves
around the tautological argument that every entity in nature is unique. The selectivity
of friction ridge skin should be fully understood from a biological perspective and
then applied in assessing latent fingermark comparisons.