Forensic recovery of identification from shell casings

Abstract

Non-destructive methods and devices are disclosed herein for overcoming the limitations associated with analyzing shell casings and other cylindrical items for biomolecular and fingerprint extraction and analysis. In a preferred embodiment of these methodologies and devices, the open end of a spent shell casing (or like object) is plugged with a handle. This approach reduces the risk of sample contamination by gunpowder residue, while also providing a convenient means for handling the shell casing that reduces the risk of contamination or sample loss. Spin baskets (or extraction tubes) are provided which may be customized to different shell casing diameters, thereby substantially reducing the volume of extraction buffer required for sample collection and enable ease of centrifugation. A strong surfactant is preferably utilized during collection, which may reduce the amount of time needed for collection to just minutes. The surfactant is preferably of a type that draws on the extracellular nature of DNA in the sample in such a way as to almost instantaneously pull it into solution upon exposure to the buffer. The full buffer volume is then rapidly collected through the spin basket for DNA purification. Additionally, the use of magnetic beads to rapidly separate DNA from metal ions and other inhibitory agents is a primary advancement of the methods. The systems and methodologies disclosed herein offer a possible paradigm shift for forensic laboratories as they analyze challenging types of casework evidence. In particular, these systems and methodologies may be utilized to improve the preservation, recovery and analysis of DNA, proteins, other forensically-relevant biomolecules, chemical, radiological, nuclear, or explosive residues, and fingerprints collected from shell casings or other like samples.