Possibility VS Practicality; A Study of the Sequential Processing of Fired Cartridge Casings

There are unrealistic expectations of the forensic science discipline by the public today. More specifically about the types of evidence that can be recovered from a fired cartridge casing. The common misconception with the evidence that can be recovered from a cartridge casing is that all three types of evidence: DNA, latent prints, and firearms can be recovered from the same cartridge casing. However, just because some analyses are possible does not mean that they are practical. The definition of possibility is that an event can happen. However, the definition of practicality is not only that it can happen, but that the event should occur to optimize the efficiency of a given task. Through literature review of previous studies as well as experimental data, each discipline (DNA, latent prints, and firearms and toolmark analysis) were evaluated. For the experimental trials, three total experiments were carried out. Experiment one focused on the possibility aspect, so in experiment one the best conditions were simulated to receive a positive result. Experiment two focused on creating conditions that would occur at a crime scene, and experiment three refined those variables to serve as middle ground. After evaluation, each discipline was classified as possible and/or practical. These results were then used to determine practical sequential processing for a fired cartridge casing. After both experimentation and review, it was determined that the best possible sequential processing path for a cartridge casing collected at the crime scene to get the quickest information back is as follows: Firearms, DNA, Latent Prints.