An evaluation of two adhesive media for the recovery of DNA from latent fingermarks: A preliminary study

Abstract

Dual recovery of forensic evidence is beneficial for crime scene and evidence processing as it can potentially double the evidential value of a single source, even more so in instances of DNA fingermarks. The use of adhesive liftering media has shown comparable results to swabbing when dealing with trace DNA recovery. Gelatine lifters have displayed the potential to recover DNA from latent fingermarks with minimal alteration to friction ridge detail post application, yet their ability to recover DNA has not fully been explored. The aim of this research was to compare the use of gelatine lifters with more readily available masking tape in their ability to recover cellular material from latent fingermarks. Natural (n = 120) and sebaceous (n = 120) fingermarks were deposited and aged in time frames from fresh, 1-day, 2-day, 1-week, 2-weeks, and 1 month. DiamondTM Nucleic Acid Dye was used as a visualisation method for any DNA containing cellular material. Images of the fingermarks pre and post lifting, and on the lifting media were imaged using the DSC®5 system. The media’s ability to recover cellular material was assessed using fluorescent particle analysis by the employment of the free software ImageJ. Fluorescent particles could be observed on the lifting media post lifting with the use of DiamondTM Dye. Time was not seen to influence the variation in the number of fluorescent particles observed. The use of gelatine lifters was found to have a higher amount of recovered DNA containing cellular material than masking tape. Visualisation of particles on masking tape were inhibited by its porosity and absorption of the dye. Some fingermark detail could be observed in the gelatine lifters. The DSC®5 system was suitable for imaging fingermarks stained with DiamondTM Dye.