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Forensic entomology is an important field of forensic science that utilizes insect evidence in criminal investigations. Blow flies (Diptera: Calliphoridae) are among the first colonizers of remains and are therefore frequently used in determining the minimum postmortem interval (mPMI). Blow fly development, however, is influenced by a variety of factors including temperature and feeding substrate type. Unfortunately, dietary fat content remains an understudied factor on the development process, which is problematic given the relatively high rates of obesity in the United States. To study the effects of fat content on blow fly development we investigated the survivorship, adult weight and development of Lucilia sericata (Meigen; Diptera: Calliphoridae) and Phormia regina (Meigen; Diptera: Calliphoridae) on ground beef with a 10%, 20%, or 27% fat content. As fat content increased, survivorship decreased across both species with P. regina being significantly impacted. While P. regina adults were generally larger than L. sericata across all fat levels, only L. sericata demonstrated a significant (P < 0.05) difference in weight by sex. Average total development times for P. regina are comparable to averages published in other literature. Average total development times for L. sericata, however, were nearly 50 hours higher. These findings provide insight on the effect of fat content on blow fly development, a factor that should be considered when estimating a mPMI. By understanding how fat levels affect the survivorship and development of the species studied here, we can begin improving the practice of insect evidence analysis in casework.
Beginning in the early 1990s, nuclear forensic science is a relatively young field that focuses on “re-establishing the history of nuclear material of unknown origin” (Mayer, et al. 2010, p. 1). Specifically, investigators compare these unknown materials, pre-detonation in this case, based on their characteristics and process history (Mayer, et al. 2010, p. 1). In 2010, the Committee of Nuclear Forensics made ten recommendations on the procedures that could lead to improvement in investigation methods. In particular, this paper discusses Recommendation 6: “The nuclear forensics community should develop and adhere to standards and procedures that are rooted in the applicable underlying principles that have been recommended for modern forensic science, including calibration using reference standards; cross-comparison with other methods; inter-laboratory comparisons; and identification, propagation, and characterization of uncertainties'' (Committee of Nuclear Forensics, 2010, p. 11). The main objective of this paper is to compile a literature review to determine how this recommendation was followed, if at all, and produce a list of suggestions that could complement any effort towards the improvement of the field. Out of the methods recommended, that which has fostered the most growth has been cross-comparison. For example, the need for human supervision has decreased, which has decreased the need for human error (Reading, et al., 2017, p. 6013). However, areas that would benefit from development are increasing the number of disciplines in the field (Croudace, et al., 2016, p. 128). These conclusions provided the basis for improvements to other existing studies like DNA and fingerprinting.