Study of unusual phenomenon of contact firing on gelatine block using .38 Special revolver--forensic importance

Gunshot wounds in suicide cases are self-inflicted wounds. Self-inflicted wounds in suicide cases are usually caused by contact firing and are of great forensic significance. Evaluation of contact wound may be associated with difficulties if the bore gets obstruction prior to firing. This paper investigates the phenomenon and interprets the results of test firing conducted on 20% gelatine block at 10 degrees C, using .38 Special revolver with obstruction of a bullet in the bore. Test firings were conducted in three different muzzle-target contact conditions keeping the muzzle pressed against the gel block in each case. The physical evidence and the wound ballistic parameter namely bullet track, remaining velocity of the bullets and volume of permanent cavity have been studied. When compared with the results of contact firing conducted with the same firearm without having any bore obstruction under similar conditions, it has been found that the physical evidence and the wound ballistic parameters would be helpful for interpretation of such unusual incidents for forensic inference.     

The many faces of access: reasons for medically nonurgent emergency department visits

Investigating why people use the hospital emergency department (ED) for visits considered medically nonurgent can enhance our understanding of people's expectations of health care services, of their conceptions of prudent lay judgment, and of difficulties in negotiating the logistics of primary care services. This study identified reasons for such ED use from users' perspectives in both pediatric and adult visits. Respondents were asked to explain what brought them to the ED and to define an emergency. The study was conducted in two northeastern U.S. hospital EDs. The analysis drew on a convenience sample of 408 (331 pediatric, 77 adult users) face-to-face interviews that employed both open- and closed-ended questions. Findings indicate most patients had medical insurance and a regular place of care and most arrived by car or taxi. Twelve main themes emerged under three main categories: conceptions of needs, appropriateness, and preference for the ED. The findings indicate that various reasons for ED use may be construed as access issues. These include beliefs regarding limited availability of after-hour consultation services and of timely appointments at one's primary care site. Drawing on the findings, a typology that distinguishes between groups of users according to their preference for the ED, a level of congruence between their own reason and their definition of an emergency was developed. The typology suggests that people's concerns that influence their decision to come to the ED cannot be solved simply by expanding primary care services or by educational interventions. Its application yields recommendations for services and interventions.     

Assessing allegations of domestic violence in child custody evaluations

There has been an increased focus on child custody evaluations involving domestic violence allegations with much criticism of evaluators' training, practices, and procedures. A national survey of 115 child custody evaluators (doctoral and master's level) was conducted to explore these criticisms. Findings revealed adequate training, multiple sources of data collection, and practices/procedures that closely adhere to child custody guidelines. However, robust, specialized domestic violence instruments, tests, and questionnaires were underutilized. Respondents indicated that findings supporting domestic violence allegations had a substantial impact on their subsequent recommendations. Results are discussed in terms of the importance of assessing domestic violence when conducting custody evaluations and the need for developing practice standards in this domain. Generally, results did not support common criticisms of custody evaluation practice.     

Context effects in forensic science: a review and application of the science of science to crime laboratory practice in the United States.

This article discusses the phenomenon of "context effects" by reviewing the findings and practices of a range of scientific fields, including astronomy, physics, biology, medicine, and especially the relevant research and theory from psychology. Context information, such as expectations about what one is supposed to see or conclude, has been found to have a small but relentless impact on human perception, judgment, and decision-making. The article then considers the vulnerability of forensic science practice to context effects, and concludes by suggesting that forensic science adopt practices familiar in other fields of scientific work, in particular blind or double-blind testing and also the use of evidence line-ups.     

Mechanisms of unexpected death in tuberous sclerosis

Tuberous sclerosis complex is a protean autosomal dominant disorder characterized by multifocal tissue lesions arising from defects in cellular migration, proliferation, and differentiation. It has an association with sudden death. In the current study, review of all cases of sudden death due to tuberous sclerosis was undertaken at the Forensic Science Centre in Adelaide, Australia from 1991 to 2001, in addition to an analysis of cases from the literature. There were two local cases where unexpected death had occurred in individuals with known tuberous sclerosis, involving a 31-year-old male (epilepsy), and a 24-year-old female (massive hemorrhage into a renal angiomyolipoma). Fatal mechanisms in cases of tuberous sclerosis may be associated with underlying cardiovascular, renal and cerebral abnormalities. Sudden death may be due to cardiac arrhythmia, epilepsy, and intra-tumoral hemorrhage with additional complications including cardiac outflow obstruction, obstructive hydrocephalus, aneurysm rupture, and spontaneous pneumothorax. An awareness of the highly variable tissue manifestations of tuberous sclerosis and the mechanisms that may be responsible for death is necessary to establish correctly the diagnosis in occult cases (possibly with molecular confirmation), and to chart accurately organ changes in individuals with established disease.     

The fingernails of Mary Sullivan: developing reliable methods for selectively isolating endogenous and exogenous DNA from evidence

The fingernails of Mary Sullivan, the last victim of the Boston Strangler, were examined to determine if any genetic information about the murderer could be obtained. The nails were extremely friable necessitating the development of new techniques for isolating and purifying DNA. DNA yields from nails were optimized by using a NaOH-based preparation technique, which was simple, efficient, and minimized handling. Methods for selectively and thoroughly removing exogenous material on nails were also developed through use of a species-specific PCR assay, wherein mitochondrial DNA from the nail could easily be differentiated from DNA of contaminating cells.     

Trends in explosive contamination

This study sought to assign a rough order of magnitude for the amount of explosive residue likely to be available in real-world searches for clandestine explosives. A variety of explosives (TNT, TATP, HMX, AN, RDX, PETN) in various forms (powder, flake, detonating cord, plastic) were carefully weighed or cut into containers, and the amount of residue inadvertently remaining on the work area, hands, or containers was quantified. This was used to evaluate the spillage potential of each explosive. The adhesion of each explosive to a glass surface was quantified from amount of explosive adhering to the inside of a glass vial into which the explosive had been placed and then removed by vigorous tapping. In powdered form, most of the explosives--TNT, PETN, RDX, HMX, and TATP--exhibited similar spillage and adhesion to glass. However, PETN as sheet explosive and plasticized RDX (C-4), showed very little potential to contaminate surfaces, either by spillage or adhesion to glass.