Effects of Decomposition on Gunshot Wound Characteristics: Under Cold Temperatures with No Insect Activity

Abstract:  Information on gunshot wound characteristics has been well documented; however, there is little documented information on the effects of decomposition or environmental conditions on gunshot wound characteristics. This study was conducted in order to determine if decomposition would obscure or alter the physical surface characteristics of gunshot wounds when exposed to a low temperature environment. The study was conducted from November 2005 to January 2006 in Nova Scotia, Canada in forested and exposed environments, with air temperatures between −10°C and +10°C. Pigs were used as human models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Gunshot wound characteristics persisted until the wounds were covered with ice and snow, after which changes were observed. The changes were recognized as being unique to the different ranges of gunshots and it was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence.     

Determination of Trace Elemental Concentrations in Document Papers for Forensic Comparison Using Inductively Coupled Plasma–Mass Spectrometry

Abstract:  With improvements in manufacturing procedures, comparing physical characteristics of paper samples may not offer sufficient discrimination among different vendors. In this work, the potential to differentiate paper samples based on trace element concentrations was investigated. Paper samples from two different vendors were microwave-digested and trace element concentrations (Mg, Al, Mn, Fe, Sr, Y, Ba, Ce, and Nd) were determined using inductively coupled plasma–mass spectrometry. Differences in concentration were assessed statistically using two-way ANOVA and Tukey's honestly significant differences test. Elemental concentrations were shown to be consistent across a single sheet as well as within a single ream of paper for each vendor. Reams from vendor A were differentiated based on Al and Ba concentration while reams from vendor B were differentiated based on Mg, Mn, and Sr concentrations. Paper was differentiated according to vendor based on significant differences in Ba, Sr, Ce, and Nd concentrations.     

Developing a Spatial-Temporal Method for the Geographic Investigation of Shoeprint Evidence

Abstract:  This article examines the potential of a spatial-temporal method for analysis of forensic shoeprint data. The large volume of shoeprint evidence recovered at crime scenes results in varied success in matching a print to a known shoe type and subsequently linking sets of matched prints to suspected offenders. Unlike DNA and fingerprint data, a major challenge is to reduce the uncertainty in linking sets of matched shoeprints to a suspected serial offender. Shoeprint data for 2004 were imported from the Greater London Metropolitan Area Bigfoot database into a geographic information system, and a spatial-temporal algorithm developed for this project. The results show that by using distance and time constraints interactively, the number of candidate shoeprints that can implicate one or few suspects can be substantially reduced. It concludes that the use of space-time and other ancillary information within a geographic information system can be quite helpful for forensic investigation.     

Vicious Dogs: The Antisocial Behaviors and Psychological Characteristics of Owners

Abstract:  Each year, 4.7 million people are bitten by dogs. Of those bitten each year, 386,000 are seriously injured and some killed. Consequently, many insurance companies refuse to issue homeowners insurance to owners of specific breeds of dogs considered "vicious" or high risk of causing injury. This study examined whether vicious dog owners were different on antisocial behaviors and personality dimensions. A total of 869 college students completed an anonymous online questionnaire assessing type of dog owned, criminal behaviors, attitudes towards animal abuse, psychopathy, and personality. The sample was divided into four groups: vicious dog owners, large dog owners, small dog owners, and controls. Findings revealed vicious dog owners reported significantly more criminal behaviors than other dog owners. Vicious dog owners were higher in sensation seeking and primary psychopathy. Study results suggest that vicious dog ownership may be a simple marker of broader social deviance.     

The Identification of a Human Skull Recovered from an eBay Sale

Abstract:  A human skull seized by the State of Louisiana from an eBay sale is analyzed. Bioarchaeological analyses of age-at-death, sex, and population affinity suggest the individual represented by the skull was a middle-aged Native American female. The presence of intentional cranial modification independently supports the population affinity assessment while confounding the metric analyses. However, no further specificity as to population affinity could be inferred using existing methods and comparative databases. Sedimentological and palynological analyses were attempted to redress this impasse. The presence of fine-grained charcoal, abundant fungal remains, and small angular quartz grains suggestive of burial in loess, as well as the lack of pollen, pteridophyte spores, and microscopic algae, suggest a likely upland burial location from somewhere in the lower Mississippi Valley. The sedimentological and palynological analyses, while not conclusive, show promise for use in future affiliation analyses of human remains recovered during the course of forensic investigations. The results are reviewed within the broader context of the legal debate over the repatriation of human remains.     

Trajectory Reconstruction Through Analysis of Trace Evidence in Bullet–Intermediate Target Interaction by SEM/EDX

Abstract:  A young male was shot to death by a police officer with a Chinese Type 64 7.62 mm pistol when he was dealing with an aggravated assault arising from a traffic accident. By using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDX), trace deposits on the discharged bullet and the intermediate target, i.e., a concrete telegraph pole at the scene, were identified to be from each other. The result demonstrated the bullet causing the death ricocheted from the concrete telegraph pole before striking the victim, thus indicating the incident was accidental. The case report illustrates the evidential value of trace materials derived, respectively, from discharged bullets and intermediate targets in bullet–intermediate target interaction for trajectory reconstruction. In addition, it indicates that the SEM/EDX method with its nondestructive nature, compared to other methods, may be more helpful in certain situations in determining the origins of trace evidentially valuable deposits on substrates.     

Walk and Die: An Unusual Presentation of Head Injury

Abstract:  We report three deaths in young adult males following closed blunt trauma to the head and face where the affected individuals were able to walk away from the incident, before subsequently collapsing and dying a short distance from the site of the assault. In each case, due to the rapidity of the posttrauma collapse, the pathologist was faced with a diagnostic difficulty at autopsy; the external examination revealed multiple injuries to the head and face, but internal examinations showed limited findings with no structural explanation for the death. We discuss possible mechanisms that could account for this scenario, the implications of alcohol consumption with a concussive head injury, and parallels that can be drawn with the so-called "talk and die,""talk and deteriorate," and "second impact syndrome." Finally, the possible role of so-called "postexercise peril" is discussed in relation to these deaths.     

Individual Camera Identification Using Correlation of Fixed Pattern Noise in Image Sensors

Abstract:  This paper presents results of experiments related to individual video camera identification using a correlation coefficient of fixed pattern noise (FPN) in image sensors. Five color charge-coupled device (CCD) modules of the same brand were examined. Images were captured using a 12-bit monochrome video capture board and stored in a personal computer. For each module, 100 frames were captured. They were integrated to obtain FPN. The results show that a specific CCD module was distinguished among the five modules by analyzing the normalized correlation coefficient. The temporal change of the correlation coefficient during several days had only a negligible effect on identifying the modules. Furthermore, a positive relation was found between the correlation coefficient of the same modules and the number of frames that were used for image integration. Consequently, precise individual camera identification is enhanced by acquisition of as many frames as possible.