The use of the likelihood ratio for evaluative and investigative purposes in comparative forensic handwriting examination

This paper extends previous research and discussion on the use of multivariate continuous data, which are about to become more prevalent in forensic science. As an illustrative example, attention is drawn here on the area of comparative handwriting examinations. Multivariate continuous data can be obtained in this field by analysing the contour shape of loop characters through Fourier analysis. This methodology, based on existing research in this area, allows one describe in detail the morphology of character contours throughout a set of variables. This paper uses data collected from female and male writers to conduct a comparative analysis of likelihood ratio based evidence assessment procedures in both, evaluative and investigative proceedings. While the use of likelihood ratios in the former situation is now rather well established (typically, in order to discriminate between propositions of authorship of a given individual versus another, unknown individual), focus on the investigative setting still remains rather beyond considerations in practice. This paper seeks to highlight that investigative settings, too, can represent an area of application for which the likelihood ratio can offer a logical support. As an example, the inference of gender of the writer of an incriminated handwritten text is forwarded, analysed and discussed in this paper. The more general viewpoint according to which likelihood ratio analyses can be helpful for investigative proceedings is supported here through various simulations. These offer a characterisation of the robustness of the proposed likelihood ratio methodology.     

A validated method for the analysis of cannabinoids in post-mortem blood using liquid-liquid extraction and two-dimensional gas chromatography-mass spectrometry

Phenazepam is a long-acting benzodiazepine that, unlike other benzodiazepines, is currently not scheduled as a narcotic in Finland, most other European countries or the USA. It is used as an anxiolytic, sedative-hypnotic and anti-epileptic, mainly in Russia. In Finland, as well as in some other countries, an increase in the unauthorized use of phenazepam has been observed in recent years. In the one year period between July 1, 2010 and June 30, 2011 the prevalence of phenazepam in Finland was assessed among drivers apprehended for driving under the influence of drugs (DUID), in medico-legal autopsy cases and in police confiscations of illicit drugs. In DUID cases an LC-MS/MS method preceded by solid phase extraction was used for the determination of phenazepam. In the post-mortem investigations the sample preparation consisted of liquid-liquid extraction followed by derivatization and the determination was carried out by GC-MS. The police confiscations were analysed by GC-MS. There were 141 positive phenazepam cases among apprehended drivers, representing approximately 3.5% of all confirmed drug cases (n=4007) in this time period. The median (range) phenazepam blood concentration in DUID cases was 0.061 mg/L (0.004-3.600 mg/L). The median phenazepam concentration in cases with no concomitant stimulant use was significantly higher than the overall median concentration. Phenazepam was found in 17 medico-legal autopsy cases and the median (range) blood concentration was 0.048 mg/L (0.007-1.600 mg/L). Phenazepam was not considered by the medico-legal team to be the sole cause of death in any of the cases, the majority of them being accidental opiod overdoses. There were 26 seizures of phenazepam by the Police in the time period studied, some of the batches consisted of a mixture of phenazepam and stimulant designer drugs. The data show that phenazepam abuse is a widespread phenomenon in Finland. A typical user was a male multi-drug user in his 30s. The concentration range of phenazepam among apprehended drivers and medico-legal autopsy cases was wide and the drug was usually found along with other psychoactive drugs. Therefore, although it seems likely that phenazepam contributed to impairment of driving in some DUID cases, the extent of its effect remains unclear and further studies are needed to define the concentrations causing impairment and toxicity.     

Antiforeigner Resentment as a Manifestation of Xhosa Hegemonic Masculinity

Abstract

During a xenophobia and social cohesion research project conducted by the Safety and Violence Initiative (SaVI) of the University of Cape Town (UCT) and Freedom House USA, researchers found an overwhelming perception that foreign nationals were taking things that belong to South Africans. This perception was most prevalent in the male population, and antiforeigner resentment was mainly aimed toward male foreign nationals. This paper uses ethnographic research in the form of qualitative interviews from Motherwell and Makhanda in the Eastern Cape province to find out how constructions of hegemonic masculinities at the local level contribute to antiforeigner resentment.     

Understanding Political Knowledge and its Influence on Voting Preferences in the 2007 Federal Election

In this article we propose a model to explain how voters’ perceptions of their ideological proximity to a party affect their propensity to vote for that party. We argue that political knowledge plays a crucial moderating role in the relationship between party proximity and voting propensity. It is necessary, however, to distinguish between institutional knowledge (information about the political system) and party knowledge (information about the parties’ left–right positions). An analysis of survey data from the 2007 Swiss federal elections supports our main hypothesis that party knowledge enhances the link between party proximity and voting propensity. Institutional knowledge may have additional influence, but clear evidence for this effect was obtained only for propensities to vote for the Swiss People's Party (SVP). Overall, the impact of political knowledge was found to be substantial, even after controlling for the outstanding influence of party identification and other predictors of voting propensities.     

Forensic Analysis of Digital Dynamic Signatures: New Methods for Data Treatment and Feature Evaluation

This study explored digital dynamic signatures containing quantifiable dynamic data. The change in data content and nature necessitates the development of new data treatment approaches. A SignPad Omega digitizing tablet was used to assess measurement reproducibility, as well as within‐writer variation and the occurrence of correctly simulated features. Measurement reproducibility was found to be high except for pressure information. Within‐writer variation was found to be higher between days than on a same day. Occurrence of correct simulation was low for features such as signature size, trajectory length, and total signature time. Feature discrimination factors combining within‐writer variability and the occurrence of correctly simulated features were computed and show that signature size, trajectory length, and signature time are the features that perform the best for discriminating genuine from simulated signatures. A final experiment indicates that dynamic information can be used to create connections between simulation cases.