DNA from Fingerprints: Attempting Dual Recovery

DNA and Fingerprints are highly prioritised evidence types as they are considered reliable when distinguishing between individuals within a population. Attempts have been documented on recovering both forms of evidence from a single source, but were met with varying success. These studies have however highlighted issues concerning interferences resulting from the methods used to either recover or visualise, with a significant issue lying with contamination or destruction of the DNA by fingerprint enhancement techniques. The aim of the research was to recover DNA prior to enhancement to determine the extent of recovery and damage of both the ridge detail and DNA. Fingerprints were deposited on textured plastic, carrier bags, glass, stainless steel and paper. DNA was recovered by the use of nylon flocked swabs (CopanTM), minitapes (ScenesafeTM) or gelatine lifts (Crime Scene Investigation LimitedTM). Extraction was conducted with QIAmp DNA micro kitTM (QIAGEN®), with Qubit® fluorometry being used for DNA quantification and NGM SelectTM (AmpFISTR®) determining the quality. For fingerprint enhancement; cyanoacrylate, aluminium powder and DFO were used to visualise the prints which were scored using the Centre of Applied Science and Technology (CAST) grading scheme. The gelatine lifts displayed higher detectable levels of DNA along with recovering more donor alleles. The lifts also resulted in the least amount of damage to ridge detail. Minitapes followed in both DNA levels and ridge damage. The nylons swabs displayed a low affinity for collecting DNA while removing all traces of the fingerprints.