Comparison between fingerprints of the epidermis and dermis: Perspectives in the identifying of corpses.

In forensic science, the putrefaction, maceration, mummification or burning make it difficult to collect the fingerprints of the epidermis for identification purposes. In such cases, the comparison between fingerprints collected from the dermal surface and the ante mortem pattern of the epidermal surface archived in databases must be performed. Therefore, considering that the identification of corpses is done by comparison of fingerprints on different surfaces, this study aimed to compare the epidermal and the dermal fingerprints to determine the discrepancies between the minutiae of both surfaces. The study was conducted with excised fingers of 19 fresh adult corpses. Once selected, excised and photographed, the fingers were subjected to maceration with 0.5% acetic acid solution for the removal of the epidermal glove and for registering the dermal fingerprint. Then, an area of 1cm(2) in the epidermal and dermal photographies was selected and the minutiae of each were separately marked by an expert in identification. The comparison between minutiae of the epidermal and dermal surfaces showed that: (1) both surfaces maintained the patterns and characteristics of fingerprints (arch, whorl or loop) and the characteristics related to the systems and the disposal of the lines, meaning the formation or not of deltas; (2) the total number of marked minutiae did not differ between both surfaces for the group of individuals (paired t test, p=0.48); (3) the percentage of coincidences and divergences (minutiae present on only one surface) between minutiae were 63.0±20.0% and 37.0±20.0%, respectively; (4) identification was possible for 16 fingers/individuals, but not for 3 of them; (5) the increase in the number of marked minutiae does not affect the percentage of coincidences. Our results demonstrate the feasibility of the dermal surface for identification purposes due to the high percentage of matching minutiae, but considering the discrepancies and the inconclusive identification of 3 fingers/individuals, our study points to the use of more fingers per individual, as well as the possibility of further studies to improve on the techniques for increasing the identification of corpses, or even to deploy new technologies to ensure their rapid and safe identification.