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.     

A fast and safe non-bleaching method for forensic skeletal preparation

Over the last three decades, forensic anthropologists increasingly have consulted on fleshed human remains cases in which the examination of skeletal elements is critical in answering questions of identification and the circumstances of death. This was certainly the case at the Human Identification Laboratory in Tucson, Arizona. As the caseload increased, it became clear that a method for defleshing human remains was needed in order to expeditiously expose the osseous surfaces for analysis, yet at the same time, preserving the evidentiary nature of the material. As a result, a fast, safe and economical method for defleshing human remains and producing high quality, degreased skeletal elements was developed. This non-bleaching cooking method utilizes chemicals that are easily obtained and inexpensive standard household ingredients that can be purchased at most grocery stores.     

Immunochemical screening: manipulation, handling and interpretation errors, exemplified by benzodiazepines

The article describes problems related to immunochemical screening-tests with special regard to benzodiazepines, which are commonly used for therapeutic purposes. Focal points are adulteration, manipulation and handling of samples, the selection of cut-off-values, specificity and cross-reactivity, influence of biotransformation and frequently observed pitfalls in the interpretation of the analytical results.     

Reliability of bloodhounds in criminal investigations

Anecdotal evidence and legend have suggested that bloodhounds are capable of trailing and alerting to a human by his or her individual scent. This same evidence may be presented to a court of law in order to accuse a particular suspect or suspects of a crime. There is little to no scientific evidence confirming the bloodhound's ability to trail and discriminate the scent of different individual humans. Eight bloodhounds (3 novice and 5 veteran), trained in human scent discrimination were used to determine the reliability of evidence, garnered through the use of bloodhounds, in a court of law. These dogs were placed on trails in an environment that simulated real-life scenarios. Results indicate that a veteran bloodhound can trail and correctly identify a person under various conditions. These data suggest that the potential error rate of a veteran bloodhound-handler team is low and can be a useful tool for law enforcement personnel.     

Fatal diphenhydramine intoxication in infants

Diphenhydramine is an antihistamine available in numerous over-the-counter preparations. Often used for its sedative effects in adults, it can cause paradoxical central nervous system stimulation in children, with effects ranging from excitation to seizures and death. Reports of fatal intoxications in young children are rare. We present five cases of fatal intoxication in infants 6, 8, 9, 12, and 12 weeks old. Postmortem blood diphenhydramine levels in the cases were 1.6, 1.5, 1.6, 1.1 and 1.1 mg/L, respectively. Anatomic findings in each case were normal. In one case the child's father admitted giving the infant diphenhydramine in an attempt to induce the infant to sleep; in another case, a daycare provider admitted putting diphenhydramine in a baby bottle. Two cases remain unsolved; one case remains under investigation. The postmortem drug levels in these cases are lower than seen in adult fatalities. We review the literature on diphenhydramine toxicity, particularly as it pertains to small children, and discuss the rationale for treating these cases as fatal intoxications.     

Polydrug fatality involving metaxalone

A 29-year old female with a history of depression was found dead in a hotel room. The death scene investigation found empty pill bottles and an empty liter bottle of wine. Metaxalone, a centrally acting muscle relaxant, along with citalopram, ethanol, and chlorpheniramine were identified in the postmortem samples and quantitated by gas chromatography-mass spectrometry. The concentration of metaxalone in femoral vein blood was 39 mg/L. The heart blood concentration was 54 mg/L. Femoral vein blood concentrations of citalopram and chlorpheniramine were 0.77 mg/L and 0.04 mg/L, respectively. Ethanol levels were 0.13 g/dL in vitreous and 0.08 g/dL in heart blood. Other tissue samples were also analyzed. The authors consider the metaxalone concentrations toxic and potentially fatal. The citalopram concentrations were lower than those reported in fatal cases for this drug alone. Death was ascribed to polydrug abuse/overdose with metaxalone a major contributor. This represents the first reported case to our knowledge in which a metaxalone overdose significantly contributed to death.