Screening of gunshot residues using desorption electrospray ionisation-mass spectrometry (DESI-MS)

Several studies have indicated that there are potential environmental sources of particles resembling inorganic primer found in gunshot residues (GSR); as a consequence examiners are reluctant to unambiguously assign the origin of inorganic particles. If organic gunshot residues (OGSR) were found in combination with inorganic particles, the possibility of environmental sources could be potentially eliminated, thereby significantly enhancing the strength of the evidence. Methods have been previously described whereby GSR specimens can be analysed for the presence of OGSR or inorganic GRS (IGSR). However, no methods have been reported that allow the analysis of both OGSR and IGSR on the same specimen. Described in this article is a direct method using desorption electrospray ionisation-mass spectrometry (DESI-MS) for the detection of methyl centralite (MC), ethyl centralite (EC) and diphenylamine (DPA) on adhesive tape GSR stubs typically used for scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) analysis. The optimisation of numerous parameters was conducted using an experimental design. The results indicate that direct analysis of these organic components of GSR is possible although some limitations were also identified. This initial investigation has also indicated that subjecting stubs to DESI analysis does not interfere with subsequent SEM-EDX analysis of primer residues; therefore the technique described herein allows a comprehensive examination of GSR that would be highly probative in the event that both OGSR and IGSR are detected in the same specimen.     

Society of Hair Testing guidelines for drug testing in hair

The Society of Hair Testing (SoHT) Guidelines for Drug Testing in Hair provide laboratories with recommended best practice guidelines whether they are currently offering drug testing in hair, or plan to offer a hair testing service in the future. The guidelines include reference to recommended sample collection and storage procedures, through sample preparation, pre-treatment and analysis and the use of cut-offs.     

Comparing recidivism rates of treatment responders/nonresponders in a sample of 413 child molesters who had completed community-based sex offender treatment in the United kingdom

Analysis of psychometric data from a sample of 413 child molesters who had completed a U.K. probation-based sex offender treatment program was carried out to assess (a) the effectiveness of therapy in the short term and (b) the longer term implications of treatment in relation to sexual recidivism. It was found that 12% (51 offenders) of the sample had recidivated within 2 to 4 years. Of these recidivists, 86% (44 offenders) had been reconvicted for a sexually related offense. One hundred thirty-five offenders (33%) demonstrated a treated profile (i.e., demonstrated no offense-specific problems and few, or no, socioaffective problems at the posttreatment stage). This group was compared with a sample of offenders deemed as not responding to treatment, matched by their levels of pretreatment risk/need. It was found that a significantly smaller proportion (n = 12, 9%) of treatment responders had recidivated, compared to the treatment nonresponders (n = 20, 15%), indicating a 40% reduction in recidivism in those who had responded to treatment (effect size = .18). Matching length of treatment to the offenders' level of pretreatment risk/need (i.e., higher risk/treatment-need offenders typically undertook longer treatment) reduced the rate of recidivism among this group to the level of recidivism observed among the lower risk/need offenders.     

Segmental hair analysis can demonstrate external contamination in postmortem cases

Excluding laboratory mistakes, a false positive hair result can be observed in case of contamination from environmental pollution (external contamination) or after drug incorporation into the hair from the individual body fluids, such as sweat or putrefactive fluid (post mortem artifact). From our 20 years experience of hair testing, it appears that artifact(s) cannot be excluded in some post mortem cases, despite a decontamination procedure. As a consequence, interpretation of the results is a challenge that deserves particular attention. Our strategy will be reviewed in this paper, based on six cases. In all cases, a decontamination procedure with two washes of 5 ml of dichloromethane for 5 min was performed and the last dichloromethane wash was negative for each target drug. From the histories, there was no suspicion of chronic drug use. In all six cases, the concentrations detected were similar along the hair shaft, irrespective of the tested segment. We have considered this as indicative of external contamination and suggested to the forces or the judges that it is not possible to indicate exposure before death. In contrast to smoke, it seems that contamination due to aqueous matrices (sweat, putrefactive fluid, blood) is much more difficult to remove. To explain potential incorporation of 7-aminoflunitrazepam via putrefactive material, the author incubated negative hair strands in blood spiked at 100 ng/ml and stored at +4°C, room temperature and +40 °C for 7, 14 and 28 days. After routine decontamination, 7-aminoflunitrazepam tested positive in hair, irrespective of the incubation temperature, as early as after 7 days (233-401 pg/mg). In all periods, maximum concentrations were observed after incubation at room temperature. The highest concentration (742 pg/mg) was observed after 28 days incubation at room temperature. It is concluded that a standard decontamination procedure is not able to completely remove external contamination in case of post mortem specimens. Homogenous segmental analyses can be probably indicative of external contamination and therefore a single hair result should not be used to discriminate long-term exposure to a drug. Nor should the presence of a metabolite be considered as a discrimination tool, as it can also be present in putrefactive material.     

Can “disciplined passion” overcome the cynical view? An empirical inquiry of evaluator influence on police crime prevention program outcomes

Objectives

Investigate the degree and nature of influence that researchers have in police crime prevention programs and whether a high degree of influence is associated with biased reporting of results.

Methods

Meta-analytic inquiry of experimental and quasi-experimental studies (n?=?42), drawn from four Campbell Collaboration systematic reviews of leading police crime prevention strategies: problem-oriented policing, ??hot spots?? policing, ??pulling levers?? policing, and street-level drug enforcement.

Results

Larger program effects are not associated with studies with higher involvement on the part of the evaluator (e.g., assisting in strategy design, monitoring implementation, overcoming implementation problems).

Conclusions

This study does not find support for the cynical view, which holds that researchers have a personal stake in the program or are pressured to report positive results. Importantly, the evaluator??s involvement in the implementation of the program may be a necessary condition of successfully executed police experiments in complex field settings.