Isotope ratio mass spectrometry as a tool for forensic investigation (examples from recent studies).

The versatility of isotope ratio mass spectrometry is demonstrated by reference to diverse case studies. Variations in the natural isotopic composition of non-biological, organic materials are compared as a means by which samples may be associated or discriminated. These techniques may be used to augment or compliment conventional forensic methodologies. delta13C analysis was used to demonstrate that different masking tape had been recovered in two, apparently similar cases, involving the smuggling of money. Visually similar ecstasy tablets were compared by consideration of the delta13C and delta15N composition of MDMA extracted from the tablets. Although only a limited number of tablets were analysed, the isotopic similarity between two different seizures was sufficient to induce a guilty plea from a person suspected of possessing both. A combination of delta2H, delta13C, delta15N and delta18O together with GC-MS analyses were applied to small samples of seized heroin. Although GC-MS analysis indicated differences between the chemical composition of two of the heroin samples, isotopic analysis suggested similarities, which were confirmed by further delta2H, delta13C and delta18O isotopic analysis of the clingfilm in which the samples were wrapped.     

Drowning of a Friedreich's ataxia patient

We here report an unusual, apparently accidental death, in which weakness associated with a progressive neuromuscular disease, Friedreich's ataxia, apparently resulted in the drowning of the deceased. The possibility of neuromuscular disease as a rare cause of drownings should not be overlooked.     

Correlations on radioimmunoassay, fluorescence polarization immunoassay, and enzyme immunoassay of cannabis metabolites with gas chromatography/mass spectrometry analysis of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in urine specimens.

Results obtained from three commercial immunoassay kits, Abuscreen, TDx, and EMIT, commonly used for the initial test of urine cannabinoids (and metabolites) were correlated with the 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (9-THC-COOH) concentration as determined by GC/MS. Correlation coefficients obtained based on 26 (out of 1359 total sample population) highly relevant samples, are 0.601 and 0.438 for Abuscreen and TDx. Correlation coefficients obtained from a parallel study on a different set of 47 (out of 5070 total sample population) highly relevant specimens are 0.658 and 0.575 for Abuscreen and Emit. The immunoassay concentration levels, that correspond to the commonly used 15 ng/ml GC/MS cutoff value for 9-THC-COOH, as calculated from the regression equations are 82 ng/ml and 75 ng/ml for TDx and EMIT and 120 ng/ml and 72 ng/ml for Abuscreen manufactured at two different time periods. The difference of these calculated corresponding concentrations provides quantitative evidence of the reagent specificity differences.     

Implicit theories of criminal responsibility

Three questions relevant to insanity decisions were examined: (a) What informational cues are weighed most heavily in the attribution of criminal responsibility? (b) How do verdict forms influence these attributions? And (c) How do individuals' beliefs about insanity and responsibility influence decision making? Undergraduate subjects (n=181) responded to vignettes portraying an act by a mentally disordered defendant. Psychiatric jargon was avoided, so that attributions were not a function of diagnostic terminology. It was found that, under the traditional scheme of not guilty by reason of insanity (NGRI) vs. guilty, level of mental disorder (schizophrenia vs. personality disorder) was the primary determinant of insanity decisions. Also, insanity judgments were more likely to be made for acts performed without planful intentionality. Under the alternative scheme of NGRI vs. guilty but mentally ill (GBMI) vs. guilty, mental disorder still controlled NGRI verdicts; a bizarre act increased the likelihood of a GBMI over a guilty verdict; and the GBMI verdict option reduced markedly the proportion of psychotic defendants found NGRI and the proportion of personality disordered defendants found guilty. There were no significant differences between diagnostic groups in the likelihood of being found GBMI. Most subjects preferred to utilize the GBMI option as a compromise verdict even in the face of very severe mental illness. Attitudinal data revealed considerable variation in agreement with the classic moral logic of the insanity defense and accounted for a significant amount of the variance in insanity decisions. The implications for both social policy and future research are discussed.     

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.