GSR2005—Continuity of the ENFSI Proficiency Test on Identification of GSR by SEM/EDX

Abstract:  Within the framework of the ENFSI Expert Working Group "Firearms" a proficiency test on the detection and identification of GSR by energy-dispersive scanning electron microanalysis (SEM/EDX) is carried out in a 2 years term. The latest test was performed in 2005/2006 and was denoted as GSR2005 . Seventy-five laboratories from 28 countries participated in this proficiency test and submitted in total 83 independent data-sets. The participating laboratories were requested to determine the total number of PbSbBa containing particles on a synthetic test sample following their own laboratory specific methods of automated GSR particle search and detection by SEM/EDX. Furthermore size and position of the detected particles had to be reported by the laboratories and were evaluated statistically. The results were compiled by means of z -scores according to the IUPAC and EURACHEM guidelines—assessing individual laboratory achievements (inter-laboratory) as well as intra-laboratory performance—and were compared to the results of the previous proficiency test run GSR2003 ( 1 ). The comparison shows that there is a noticeable improvement in the method's detection capability.     

Positive identification of the principal component of a white powder as scopolamine by quantitative one-dimensional and two-dimensional NMR techniques

An unidentified white powder collected as evidence in an intelligence investigation was characterized exclusively by nuclear magnetic resonance (NMR) analysis. A small fraction of the powder dissolved in D2O was subjected to a series of one- and two-dimensional techniques which were used to elucidate the molecular structure of the powder's major component and positively identify it as the scopolamine biotoxin. Quantitative one-dimensional experiments identified individual proton and carbon atom sites, and conventional 14N spectroscopy detected a single nitrogen atom site. Heteronuclear single quantum coherence data correlated all protons to their directly bonded carbon atom, and together with the quantitative spectra, were used to determine the number of protons directly bonded to each carbon atom. The presence of a methyl, carboxyl, and a benzyl group was also identified from these data. Correlation spectroscopy detected a three proton and a nine proton JH,H network, representing a CH2CH moiety and seven carbon atom ring, respectively. These five elements were assembled into an almost complete molecular structure by using long-range, J-coupled, 1H-13C pairs detected by heteronuclear multiple bond correlation (HMBC) spectroscopy and 1H-1H dipolar-coupled pairs found from nuclear Overhauser effect spectroscopy (NOESY) data. Additional oxygen atom sites were inferred from 1H-13C correlation intensities in the HMBC spectra along with 1H and 13C chemical shift values, or directly from NOESY correlations. Only a single oxygen atom site could not be inferred from NMR data, but its presence was inferred from comparisons to target analyte structures to complete the structure of the scopolamine molecule. To confirm these results, an ethanol/H2O solution of the powder was analyzed by direct infusion into an ion trap mass spectrometer. A prominent base signal was observed at m/z 304.1 amu, corresponding to the protonated molecular ion of scopolamine. Subsequently, the ion was selected and subjected to collision-induced dissociation, producing characteristic major MS/MS fragments at m/z 138.1 and 156.1. Comparisons of 1H and 13C chemical shift values and JH,H values measured from our NMR data were found to agree very favorably with previously reported values for scopolamine in D2O.     

Cross‐Cultural Comparison of Two Serial Sexual Murder Series in Italy and the United States

Abstract: There have been few documented comparisons of serial murder cases committed in the United States with cases occurring internationally. The authors contrasted two unique serial murder series: one in Italy and one in the United States by examining the details of both series, including the M.O., motivation, crime scene interactions, sexual acts performed, and the general backgrounds of both offenders. The comparison revealed a number of similarities. Both offenders specifically targeted elderly women, who were attacked in their residences. The two series involved sexually motivated crimes, although the sexual interactions were different. Both offenders stole objects from their victims after the murders and each kept newspaper accounts of their crimes. In addition, both offenders claimed to have abusive upbringings, including sexual abuse.     

Low-intensity community supervision for low-risk offenders: a randomized,controlled trial

The Philadelphia Low-Intensity Community Supervision Experiment provides evidence on the effects of lowering the intensity of community supervision with low-risk offenders in an urban, US county community corrections agency. Using a random forests forecasting model for serious crime based on Berk et al. Journal of the Royal Statistical Society, Series A, 172(Part 1), 191–211, 2009, 1,559 low-risk offenders were identified and randomly assigned to either standard or reduced frequency of mandatory office visits. Treatment as assigned was substantially delivered at 4.5 probation visits per year versus 2.4, for as long as offenders remained on active probation or parole. In a one-year follow-up for all cases, outcomes examined were the prevalence, frequency, seriousness and time-to-failure of arrests for new crimes committed after random assignment was implemented. No significant differences (p = .05) in outcomes were found between standard and low-intensity groups. Non-significant differences for offense seriousness favored the low-intensity group. We conclude that lower-intensity supervision at the tested level of dosage can allow fewer officers to supervise low-risk offenders in the community without evidence of increased volume or seriousness of crime.