Bullet Caliber and Type Categorization from Gunshot Wounds in Sus Scrofa (Linnaeus) Long Bone

Studies on ballistic trauma to the ribs and thorax, cranium, and long bones demonstrate the potential of obtaining a bullet caliber from an entrance wound. In order to validate prior research on caliber estimation in bone tissue and assess the viability of bullet type determination based on the macroscopic evidence at the entrance wound, thirty fleshed pork (Sus scrofa) shoulders (humeri) were shot with either lead or copper jacketed bullets in one of three calibers; 0.22, 9 mm, or 0.38. Overall, our findings are consistent with previous research indicating that calibers can be grouped into “small” and “large” categories. Bullet type, lead or copper jacket, can be ascertained based on cortical flaking and the analysis of materials deposited around the entry wound. The addition of this evidence holds value in cases where no firearm or ballistic evidence is recovered from a crime scene.     

Mass grave localization prediction with geographical information systems in Guatemala and future impacts

Conducting physical searches for mass grave locations based on anecdotal evidence is a time-consuming and resource-intensive endeavor in circumstances that often pose a threat to personal safety. The development of tools and procedures to speed such searches can greatly reduce the risk involved, increase the number of individuals whose remains are recovered and identified, and more importantly, reunite these remains with their loved ones to provide them with a proper burial. Geographic information systems (GIS) software, which can analyze and manipulate the spatial characteristics of known mass grave data, represents a powerful tool that can be used to predict new mass grave locations and increase the speed and efficiency with which they are investigated. Using the open source QGIS project, existing mass grave locations in Guatemala were analyzed based on their distance from and change in elevation relative to roads, streets, waterways, points of interest, and possible villages/towns. Statistical and geostatistical analyses performed to detect relationships among the variables resulted in patterns that warrant further study and can be used to further narrow areas of investigation.     

Political environment and voluntary disclosure in the U.S.: Evidence from the Carbon Disclosure Project

We investigate whether the political leaning of the state where a given firm is headquartered is related to that firm's decision to voluntarily disclose climate change information. We study S&P 500 firms that were surveyed by the Carbon Disclosure Project (CDP) and find that firms headquartered in more Democratic states are more likely to disclose carbon emissions information to the CDP. Furthermore, firms in more Democratic states are more likely to permit public disclosure of their survey responses and tend to receive higher disclosure scores. We consider two political variables, one based on political power and one based on public political preference. Our results are consistent with political power driving the firm's willingness to voluntarily disclose information about climate change. These results suggest that the relation between the political environment and disclosure is more closely linked to concerns over regulatory threats as opposed to acquiescence to social norms.     

Evaluation of Commercial Kits for Dual Extraction of DNA and RNA from Human Body Fluids, ,

STR typing of DNA evidence can identify the donor with a high power of discrimination but cannot identify the tissue origin of a body‐fluid stain. Using RNA to attribute a crime scene stain to a particular tissue may aid in reconstruction efforts. With blood from 10 donors, four DNA and RNA coextraction kits were evaluated by measuring yields and STR and mRNA profiles. T tests indicated some significant differences in kit performance. The Zymo Research ZR‐Duet^? kit performed best based on average DNA (41.4 ng) and mRNA (4.07 ng) yields and was the only kit to provide complete DNA/RNA profiles for all samples. The consistency of this kit was challenged by data from additional blood and saliva donors. Further testing is advised before a superior kit is unequivocally chosen. Stand‐alone DNA or RNA purification generally offers higher yield, but coextraction may still allow successful STR profiling and tissue source identification.     

Geographic Variation in Zygomaxillary Suture Morphology and its Use in Ancestry Estimation

Angled/curved zygomaxillary suture coding is widely employed in cranial assessments of ancestry. However, the efficacy of this method has not been extensively evaluated across diverse populations. In this study, zygomaxillary suture morphology was assessed on a total of 411 human crania from six populations (European, Native American, African, Asian, Arctic Circle, and Aboriginal Australian) using a novel 3D coordinate landmark method. Our results indicate a predominance of angled sutures among native peoples of the Arctic and North America (85–86%), a prevalence of curved sutures among Africans and Aboriginal Australians (77–81%), and essentially equal proportions of both configurations in Asians and Europeans (50–56%). Statistically, angled/curved coding generally discriminates poorly between groups, except when populations with antithetically high frequencies of the two configurations (e.g., African vs. Native American) are compared. Moreover, comparisons across previous studies reveal conflicting frequencies for many populations, further suggesting limited utility of this trait in ancestry estimation.     

Identification of Different Forms of Cocaine and Substances Used in Adulteration Using Near‐infrared Raman Spectroscopy and Infrared Absorption Spectroscopy

Identification of cocaine and subsequent quantification immediately after seizure are problems for the police in developing countries such as Brazil. This work proposes a comparison between the Raman and FT‐IR techniques as methods to identify cocaine, the adulterants used to increase volume, and possible degradation products in samples seized by the police. Near‐infrared Raman spectra (785 nm excitation, 10 sec exposure time) and FT‐IR‐ATR spectra were obtained from different samples of street cocaine and some substances commonly used as adulterants. Freebase powder, hydrochloride powder, and crack rock can be distinguished by both Raman and FT‐IR spectroscopies, revealing differences in their chemical structure. Most of the samples showed characteristic peaks of degradation products such as benzoylecgonine and benzoic acid, and some presented evidence of adulteration with aluminum sulfate and sodium carbonate. Raman spectroscopy is better than FT‐IR for identifying benzoic acid and inorganic adulterants in cocaine.