Hazards of mattresses, beds and bedding in deaths of infants

Of 52 infants who had died suddenly and were referred to autopsy, nine had lain on adult water beds for the first time; five had died as a result of accidents; two had died on water beds; two were in beds with widely spaced slats; and one had died as a result of strangulation. Three deaths were due to overlying. Three other infants had been placed on sheepskin rugs for the first time and were found dead shortly thereafter. These infants ranged in age from 2 to 9 months, except for a severely mentally retarded nine-year-old with spastic paraplegia. We believe that a general warning should be issued concerning water beds and that soft bedding should not be used for infants. Infants should not be placed unattended or left to sleep on water beds; only beds recommended for infants should be used. Overlying of a young infant is most likely to occur on a water bed, or if the parent is obese or has consumed alcohol.     

Toxicology and Circumstances of Completed Suicide by Means Other than Overdose*

Abstract: To determine the prevalence and circumstances of psychoactive substances amongst nonoverdose completed suicide, 1436 consecutive cases autopsied at the NSW Department of Forensic Medicine over the period 1/1/1997–12/31/2006 were analyzed. Substances were detected in 67.2% of cases, and illicit drugs in 20.1%. Alcohol was present in 40.6% of cases. Males were more likely to be positive for alcohol, cannabis, and psychostimulants, and females for pharmaceuticals. Illicits were associated with younger age. Alcohol was most prominent amongst toxicity cases, as were opioids, psychostimulants amongst gunshot cases, and pharmaceuticals amongst drownings. Cases in which drug and alcohol histories were noted were more likely to have a substance detected. Alcohol was more common where a suicide note was left and where relationship problems were involved. Pharmaceuticals were more common where a previous attempt was noted. Licit and illicit substances are strongly associated with suicide, even when the method does not involve drug overdose.     

A novel histological technique for distinguishing between epithelial cells in forensic casework

There are a number of forensic cases in which the identification of the epithelial cell type from which DNA originated would provide important probative evidence. This study aimed to develop a technique using histological staining of fixed cells to distinguish between skin, buccal and vaginal epithelium. First, 11 different stains were screened on formalin-fixed, wax-embedded cells from five women. Samples were analysed qualitatively by examining staining patterns (colour) and morphology (absence or presence of nuclei). Three of the staining methods – Dane's, Csaba's and Ayoub-Shklar – were successful in distinguishing skin epithelial cells from buccal and vaginal. Second, cells were smeared directly onto slides, fixed with one of five fixatives and stained with one of the three stains mentioned above. Methanol fixation, coupled with the Dane's staining method, specific to keratin, was the only technique that distinguished between all three cell types. Skin cells stained magenta, red and orange and lacked nuclei; buccal cells stained predominantly orange–pink with red nuclei; while vaginal cells stained bright orange with orange nuclei and a blue extracellular hue. This staining pattern in vaginal cells was consistent in samples collected from 50 women aged between 18 and 67. Identification of cell type from unlabelled micrographs by 10 trained observers showed a mean success rate of 95%. The results of this study demonstrate that histological staining may provide forensic scientists with a technique for distinguishing between skin, buccal and vaginal epithelial cells and thus would enable more conclusive analyses when investigating sexual assault cases.     

Judging Bias: Juror Confidence and Judicial Rulings on Challenges for Cause

The judge in a jury trial is charged with excusing prospective jurors who will not be impartial. To assess impartiality, prospective jurors are typically asked whether they can be fair. Using an experimental paradigm, we found that small changes in jurors' self‐reported confidence in their ability to be fair affected judges' decisions about bias but did not affect the judgments of either attorneys or jurors. We suggest why a judge's role and unique relationship with jurors is likely to foster a decision strategy based on reported juror confidence, and we discuss the implications of our analysis for current legal debates over jury selection practices. Unexpected patterns in our results also highlight the ways in which perceptions of impartiality are affected, in part, by the social characteristics of the observer.     

Two examples of null alleles at the D19S433 locus due to the same 4 bp deletion in the presumptive primer binding site of the AmpFlSTR Identifiler kit

Two cases of allelic loss at the D19S433 locus after multiplex PCR with the AmpFlSTR Identifiler kit (Applied Biosystems) are described. In both cases the failure of PCR resulted in genetic inconsistencies due to opposite homozygosity. After singleplex PCR with published primers additional alleles were observed and Mendelian inheritance was restored. These PCR products were sequenced and in both cases the same 4 bp deletion near the 3′ end of the repeat region was detected in two alleles of different length. The frequency of these null alleles (two events in 1026 allelic transfers) amounts to 0.0019 (95% confidence limits: 0.0002-0.0070).     

Interrogation of short tandem repeats using fluorescent probes and melting curve analysis: A step towards rapid DNA identity screening

Current forensic DNA profiling methods rely on the analysis of samples at specialised laboratories with an average turnaround time of several days. The ability to rapidly determine a partial profile of short tandem repeats at the point-of-arrest would be of great benefit to police forces around the world, for example enabling a suspect to be rapidly included or excluded from an investigation. We have developed a homogeneous PCR method for the interrogation of STR loci utilising fluorescent oligonucleotide probes and melting curve analysis. Alleles of the D18S51, TH01 and D8S1179 loci were differentiated and identified on the basis of target length and probe melting temperature. Assay performance was evaluated by comparing melting peak data with the AmpFlSTR^® SGM Plus^® system. The method is compatible with direct analysis of unpurified buccal swab samples, enabling a partial STR profile to be generated within 1 h.