Recovery of latent fingermarks from burial environments

Background Fingermarks can be found both in indoor and outdoor crime scenes. The latter could be subjected to various types of environmental insults. In many cases, criminals try to dispose of or conceal the evidence in several ways, such as throwing in the waterways or burying in the soil to avoid detection from the law enforcement agencies. Thus, crime scene investigators often face challenges to detect and develop latent fingermarks in such environments. This study aimed to investigate the persistence and ageing of latent fingermarks in a burial environment for particular periods. To date, there is a limited study that attempted to investigate the survivability of fingermarks in a burial environment. Methodology The experiment was carried out in two settings: preliminary and main experiments. A preliminary experiment was conducted indoor to determine the most effective chemical for fingermark development on buried metal substrates. Five different chemicals were employed to develop the latent fingermarks, namely fingermark powder dusting, small particle reagent (SPR), Sudan black, oil red O, and crystal violet. The main experiment was carried out to simulate the realistic situation in which the metal substrates bearing latent fingermarks were buried in the soil within 2 months period. In both experiments, the substrates were buried in peat soil at a depth of 10 cm from the surface. Results The results demonstrated that latent fingermarks could be effectively recovered after being buried in the soil up to 8 weeks using Sudan black. The position of the substrates whether underlying in “face up” or “face down” orientations when buried had also influenced the quality of the developed fingermarks. Fingermarks buried in the “face up” position demonstrated better quality and more ridge details as compared to those buried in the “face down” position. Secondary fingermarks were also observed in this study and found to be useful for identification and must be taken into consideration when developing fingermarks on buried items in forensic cases. Conclusion The development of fingermarks recovered from burial environments is feasible as excellent ridge characteristics can still be identified. Hence, any evidence recovered from burial sites should be examined for fingermarks and cannot be discounted.