Directed Research Project
This experiment attempted to tackle the long-standing struggle to consistently recover latent fingerprints from fired cartridges. With an emphasis on realistic handling of high volume of samples combined with Cyanoacrylate fuming followed by Basic Yellow dye staining, a total of 740 cartridges were examined. These included fired and unfired brass and nickel case 9mm Luger and 40 S&W cartridges. The cartridges were divided into five different groups; each were treated differently prior to cyanoacrylate fuming and dye staining, which was conducted in the same manner for the groups. The groups included the positive and negative controls, loaded, cycled, and fired. Once collected, the groups were placed into the cyanoacrylate fuming chamber, processed, and then dipped into Basic Yellow. All results were examined by an experienced forensic latent print examiner using a Crime-Lite 42S blue/green wavelength alternate light source. The purpose of the loaded, cycled, and fired groups was to isolate the firing process and demonstrate how each step affects the enhancement latent fingerprints. As expected, there were only two (2) cartridge cases from the 500 fired cartridges that had any friction ridge detail. One requires further advanced enhancement to determine if enough characteristics could be pulled to be of value, and the other contained some characteristics, but not enough to be of value. These were on a brass case and nickel case 9mm Luger cartridge casing, respectively. The loaded and cycled groups exhibited varying degrees of friction ridge detail, ranging from “not enough contrast to see characteristics” to “good to use for comparison.” What sets this experiment apart from previous, similar studies is the prioritization of mimicking law enforcement’s actual collection, packaging, and handling methods, as well as the large number of samples.
© The Author(s)
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VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
Available for download on Wednesday, May 11, 2022