Simultaneous identification and δ¹³C classification of drugs using GC with concurrent single quadrupole and isotope ratio mass spectrometers

In this study, δ13C values of six cocaine samples were identified and classified using a single quadrupole mass spectrometer and an isotope ratio mass spectrometry (IRMS) as simultaneous gas chromatography detectors. Our instrument modification is simple to use and is useful (i) when the sample is of limited size or can only be injected once, (ii) to help identify peaks in a complicated IRMS chromatogram, and (iii) to help differentiate very simple systems when impurity profiling is not possible. The EI-MS confirmed the identity of cocaine in each sample. The IRMS data distinguished 12 of the 15 possible pair-wise comparisons at the 95% CL. Three samples could not be differentiated by their δ13C ratios for cocaine. ANOVA demonstrated that the measurement variance was consistently larger than the sample variance. As the δ13C values clearly show, this technique enables the exclusion of a potential common source even when two samples have otherwise identical chemical and physical properties.     

Intimate partner violence and HIV/STD risk among lesbian, gay, bisexual, and transgender individuals

To date, there has been little research examining HIV/STD risk among lesbian, gay, bisexual, and transgender (LGBT) individuals who are in abusive relationships. This article uses data collected from a community-based organization that provides counseling for LGBT victims of intimate partner violence (IPV). A total of 58 clients completed the survey, which inquired as to sexual violence and difficulties negotiating safer sex with their abusive partners. A large percentage of participants reported being forced by their partners to have sex (41%). Many stated that they felt unsafe to ask their abusive partners to use safer sex protection or that they feared their partners' response to safer sex (28%). In addition, many participants experienced sexual (19%), physical (21%), and/or verbal abuse (32%) as a direct consequence of asking their partner to use safer sex protection. Training counselors on issues of sexuality and safer sex will benefit victims of IPV.     

Interpreting small quantities of DNA: the hierarchy of propositions and the use of Bayesian networks

The dramatic increase in the sensitivity of DNA profiling systems that has occurred over recent years has led to the need to address a wider range of interpretational problems in forensic science. The issues surrounding questions of the kind "whose DNA is this?" have been the subject of considerable controversy but now it is clear that the emphasis is shifting to questions of the kind "how did this DNA get here?" Such issues are discussed in this paper and new insights are provided by two particular recent developments. First, the notion of the "hierarchy of propositions" that has arisen from a project called Case Assessment and Interpretation (CAI) that has been running in the British Forensic Science Service (FSS). Second, a technique for drawing inferences in the face of many interacting considerations, known as "Bayesian networks"--or "Bayes' nets" for short--that has been the subject of an earlier paper in this journal (1). The discussion is carried out by means of case studies, based on actual cases. It is clear that, whereas the inference in relation to the source of the DNA in a crime sample might be overwhelmingly strong, the inference in relation to the propositions that a jury must consider relating to the identity of the actual offender may be much more tentative.     

The Effect of Human Rights on Criminal Evidentiary Processes: Towards Convergence,Divergence or Realignment?

This article examines the contribution which the European Court of Human Rights has made to the development of common evidentiary processes across the common law and civil law systems of criminal procedure in Europe. It is argued that the continuing use of terms such as 'adversarial' and 'inquisitorial' to describe models of criminal proof and procedure has obscured the genuinely transformative nature of the Court's jurisprudence. It is shown that over a number of years the Court has been steadily developing a new model of proof that is better characterised as 'participatory' than as 'adversarial' or 'inquisitorial'. Instead of leading towards a convergence of existing 'adversarial' and 'inquisitorial' models of proof, this is more likely to lead towards a realignment of existing processes of proof which nonetheless allows plenty of scope for diverse application in different institutional and cultural settings.