Directed Research Project
The development of latent fingerprints on cartridge cases is a desirable ability for the forensic laboratory, offering the potential to provide probative evidence as to the handler of whole ammunition or fired cartridge cases discovered at the crime scene. Previous studies have focused primarily on intentionally-laid fingerprints on cartridge case surfaces, which do not represent samples likely to come across the desk of a forensic analyst. This study focuses on naturally-handled ammunition and the success rates associated with latent fingerprints produced in a more realistic set of circumstances. A comparison was performed of two fingerprint development methods—gun bluing and MBD [7-(p-Methoxybenzylamino)-4-Nitrobenz-2-oxa-1, 3-Diazole] dye staining following cyanoacrylate fuming—on two common ammunition types (brass and nickel-plated cartridge cases, caliber 9mm Luger). MBD dye staining showed a slight advantage over gun bluing based on statistical and observational results. Unfired, brass positive controls processed using MBD achieved statistically higher grades (p<0.001) than those processed using gun bluing. Gun bluing also entirely failed to yield central ridge detail on unfired brass cartridge cases. Finally, MBD was able to generate of-value fingerprints (grades 3-4) at higher rates than gun bluing in all testing groups that had a nonzero number of valuable fingerprints. For all naturally-handled, case-like samples, only a single of-value fingerprint was obtained using the MBD method on an unfired nickel-plated cartridge case. Based on the results and observations of this study, it is recommended that laboratories do not process 9mm Luger brass or nickel-plated fired cartridge cases for latent fingerprints using the MBD or Gun Bluing methods, and process unfired nickel-plated cartridge cases using the MBD method.
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VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
Available for download on Thursday, May 04, 2023