Performance evaluation of the Scent Transfer Unit (STU-100) for organic compound collection and release

The Scent Transfer Unit (STU-100) is a portable vacuum that uses airflow through a sterile gauze pad to capture a volatiles profile over evidentiary items for subsequent canine presentation to assist law enforcement personnel. This device was evaluated to determine its ability to trap and release organic compounds at ambient temperature under controlled laboratory conditions. Gas chromatography-mass spectrometry (GC-MS) analyses using a five-component volatiles mixture in methanol injected directly into a capture pad indicated that compound release could be detected initially and 3 days after the time of collection. Additionally, 15 compounds of a 39-component toxic organic gaseous mixture (10-1000 parts per billion by volume [p.p.b.(v)]) were trapped, released, and detected in the headspace of a volatiles capture pad after being exposed to this mixture using the STU-100 with analysis via GC-MS. Component release efficiencies at ambient temperature varied with the analyte; however, typical values of c. 10% were obtained. Desorption at elevated temperatures of reported human odor/scent chemicals and colognes trapped by the STU-100 pads was measured and indicated that the STU-100 has a significant trapping efficiency at ambient temperature. Multivariate statistical analysis of subsequent mass spectral patterns was also performed.     

Drug screening and confirmation by GC-MS: comparison of EMIT II and Online KIMS against 10 drugs between US and England laboratories

Drug screening through urinalysis is a widely accepted tool for rapid detection of potential drug use at a relatively low cost. It is, therefore, a potentially useful method for detecting and monitoring drug use in a variety of contexts such as the criminal justice system, pre-employment screening and a variety of treatment centers. This article explores the efficacy of two commercially available drug-screening assays: Online KIMS assay (Roche) and EMIT II assays. First, we evaluate the sensitivity and specificity of two immunoassays. A total of 738 urine samples were collected among adult arrestee populations from Chicago, New Orleans and Seattle through the Arrestee Drug Abuse Monitoring (ADAM) program. Partial samples were split within one laboratory and analyzed by both enzymes multiplied immunoassay technique (EMIT) II and kinetic interaction of microparticle in solution (KIMS) assays for a 10-drug panel (amphetamine, barbiturates, benzodiazepines, marijuana, cocaine, methadone, methaqualone, opiate, phencyclidine and propoxyphene). Gas chromatography-mass spectrometry (GC-MS) was used as a confirmation method for all positives from either EMIT II or KIMS for all experiments. Second, the paper examines whether using different testing laboratories plays a role in the final results. The same experiments were repeated at two different testing locations: one in California and one in London and England. Third, the paper studies whether drug testing results vary between two laboratories when each of them had used their own routine screening method: the Forensic Science Service (FSS) at Birmingham, United Kingdom with KIMS assay and Medscreen Limited at London, United Kingdom with EMIT II. In summary, both EMIT II and KIMS assays generate fairly consistent results. The concordance rate against each of the 10 drugs tested is relatively high (97.4-100%). The discrepancies, in most cases, occurred at drug concentrations near the cut-off levels. There were more discrepant results between two laboratories compared to when specimens were analyzed at the same laboratory using two different assays.     

Accurately assessing elderly fall deaths using hospital discharge and vital statistics data

Historically, fatal injury monitoring and surveillance have relied on mortality data derived from death certificates (DC). However, problems associated with utilizing DC have been well documented. Recently, access to and utilization of hospital discharge data (HDD) have offered a new and important secondary source of data regarding in-hospital deaths. However, studies have shown that discrepancies between the HDD and the corresponding DC often exist. This discrepancy was especially evident when comparing HDD to the vital statistics data (VSD) for deaths by falls among those aged 65 and over in 19 states.This was a retrospective forensic review of elderly (age 65 and over) fall-associated fatalities (E880-E888) identified from HDD and VSD in Allegheny County, Pennsylvania, between 1997 and 1998. Seventy-seven cases were identified, with the original manner of death listed as natural (34), suicide (1), and accidental (42) on the DC. Following a forensic review of the cases, the manner of the death on the DC should have been changed from natural to accidental in 28% (n = 12) of the cases, representing an undercount in the VSD. Undercounts were due to a failure of clinicians to account for the significance of a fall event that contributed to subsequent pathology and death. In addition, in that 22% (n = 17) of the HDD fall-associated deaths, the fall did not contribute directly or sequentially to the underlying cause of death, thereby representing an overcount in the HDD.Based on these findings we recommend (1) elderly fall surveillance systems should only count HDD E-coded falls that demonstrate a serious traumatic injury which directly or subsequently results in death, (2) all in-hospital fall-associated deaths should be reported to and reviewed by coroner/Medical Examiner offices for determination of the cause and manner of death, and (3) physicians should be better educated in properly completing death certificates.     

Identification of animal species by protein radioimmunoassay of bone fragments and bloodstained stone tools

In forensics and archaeology, it is important to distinguish human from animal remains and to identify animal species from fragmentary bones and bloodstains. We report blind tests in which a protein radioimmunoassay (pRIA) was used to identify the species of six bone fragments lacking morphological specificity and 43 bloodstained lithic tools, knapped experimentally and soaked in blood of known animal and human origin. The submitters of the bone fragments and the bloodstained tools each listed a number of possible species, from which the testers selected the best match with the pRIA results. All six bone fragments were correctly identified: three humans, a deer, a dog, and a cow. Forty-three tools were stained with blood from a wide variety of species including ungulates, carnivores, a fish, and a bird. On 40 of these 43, at least one species (or blood-free control) was identified correctly. Some of the tools were stained with blood of two different species. A mixture of sheep and musk ox blood was correctly identified; in several other mixtures, only a single species was detected. Two tools with human blood and one with human sweat were correctly reported as human. There was a single false positive (one of three controls reported as weakly bovine) and no false negatives. We conclude that the pRIA technique shows a high degree of accuracy in discriminating human from animal bone fragments and bloodstains and in identifying animal species.