Crime Scene Investigator Network Newsletter

Introduction

As one of the many fields of forensic science that can benefit from additional research, fingerprint identification is probably the most prominent. Within recent years, many latent print examiners have been questioned in both professional and social situations as to whether fingerprint evidence should be considered scientific. This questioning caused latent print examiners to realize the pressing need for various types of ongoing research on the subject of fingerprints.

Fingerprint patterns are formed on the fetus in the womb. Wertheim and Maceo reported that various cellular attachments ensure the permanence of friction ridges, while cellular stresses and cellular distributions account for the individuality on all “three levels” of detail. They also state that fingerprint ridge counts and fingerprint pattern types are predominantly affected by two combined timing events: the onset of epidermal cellular proliferation and the timing of the regression of the volar pads. The total friction ridge count, according to Holt, as reiterated by Wertheim and Maceo, is the most inheritable feature in dermatoglyphics and is also determined by the symmetry of the volar pad at the time of ridge proliferation. This, therefore, suggests that the combined timing event of the onset of ridge proliferation along with the regression of the volar pad is also an inheritable trait. Consequently, the type of fingerprint pattern that occurs on the fetus is dependent upon the combined timing events of the onset of ridge proliferation and the volar pad regression. This idea that ridge formation, alignment, and overall pattern shape are affected by the time of the volar pad’s appearance along with its regression was asserted by Cummins as early as 1929 and was still supported by Ashbaugh over sixty years later in 1991. Ashbaugh also concurs with Hale’s earlier research in 1952 where he aphoristically states that heredity dictates that volar skin will form friction ridges, also that the friction ridge pattern will follow a genetic master plan which involves volar pads. The formula is carried in our genes.

The latter is supported by numerous studies of the ridge patterns of monozygotic twins whereas it can be concluded that heredity may play a significant role in the overall ridge configuration and pattern (level 1 detail), but Wertheim and Maceo, Hale, Ashbaugh, and others all concur that it does not determine the outcome of the individual ridge growth (level 2 and 3 detail), because the ridge alignment, shape, and minutiae location all evolve randomly through various stresses and cellular distributions, thus reaffirming the individuality of fingerprints on both level 2 and 3 detail. Additionally, in their initial formation, most volar pads usually tend to swell up symmetrically and, as they regress, some tend to regress faster on one side than the other, which will account for an asymmetrical volar pad during the middle stages of volar pad regression. With that in mind, if a fetus has an early timing of the onset of ridge proliferation before the volar pad has regressed much, then the volar pad will most likely be symmetrical at the time of proliferation, resulting in a whorl fingerprint pattern. On the other hand, if a fetus has a late timing of the onset of ridge proliferation after the regression of the volar pad, then the volar pad would have already merged with the contours of the finger,

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