The data presented in this thesis has been organized in three parts: First part included the development and validation of a quantitative HPLC-DAD analytical method of mephedrone after extraction from spiked whole blood and serum samples, alone and with methcathinone. The second part included in vitro metabolism of mephedrone and other NPS, which are methoxetamine and methcathinone, using an in-house prepared in vitro metabolic system, namely liver microsomes, followed by performing analysis for the drugs and their proposed metabolites utilizing LC-MS. Third part included in vitro studies of selected NPS using purchased HepaRG and hepatocytes. In vitro study included in vitro cytotoxicity studies of 4-fluoromethamphetamine, mephedrone, methoxetamine and methcathinone, and analytical studies of these drugs of abuse and their potentially produced metabolites using GC-MS. In the first part of this thesis, a HPLC method for the analysis of mephedrone after LLE from blood matrix was developed and validated and shown to be linear with R2> 0.995, precise with intraday and interday RSD values of 4.36 and 4.77% respectively and LOD and LOQ of 0.025 and 0.082 μg/mL respectively. Recovery percentages were low and ranged between 28-37%. Emulsion formation was the major problem effaced which negatively affected recovery and precision values. The previously developed method was optimised and fully validated for the simultaneous analysis of mephedrone and methcathinone after liquid-liquid extraction (LLE) from whole blood and serum samples. The LLE method was optimised through selection of extraction solvent and adjustment of pH values achieving the best validation parameters and minimal emulsion formation. The LLE protocol involved extraction with a mixture of dichloromethane: n-butanol (80:20 v: v) after buffering the sample with borate buffer pH=9.2 and using aniline as internal standard. The HPLC-DAD method was optimized, using reverse mode chromatography and buffered mobile phase of (acetate buffer pH 4.1: ACN – 85:15) for qualitative and quantitative analysis of these drugs in less than 10 minutes under isocratic elution and ambient temperature. The method was fully validated for both drugs and showed to be linear over the specified range of 0.1-10 μg/mL with R2 > 0.99 for both drugs. The accuracy was assessed by calculating percentage recovery at different concentrations for xii both drugs, and retained recovery percent between 84-110%. For repeatability and intermediate precision tests, RSD values were ≤ 6.73%. Specificity was assessed by good resolution between the peaks and by checking peak purities. Limit of detection and limit of quantification, calculated mathematically for both drugs either extracted from whole blood or serum samples, were 0.010- 0.013 μg/ml and 0.032 - 0.043 μg/mL, respectively. In the second part, in vitro studies on the metabolism of the selected NPS using pig liver microsomes and liquid chromatography-mass spectrometry (LC-MS) analysis were performed. Microsomes were prepared by a conventional ultracentrifugation method. In brief, pig liver was brought freshly from local abattoir, sliced into small pieces, homogenised and ultra-centrifuged to produce microsomes and S9 fractions. Produced microsomes were incubated with the drugs of interest under optimised conditions and followed by analysis utilizing LC-MS for the detection of the drugs and the potentially produced metabolites. It was possible to detect two metabolites of the drug mephedrone, hydroxytolyl-mephedrone and nor-dihydro mephedrone. For MXE, one metabolite produced by the O-demethylation was detected and it identity confirmed by MS/MS study to be o-desmethyl-MXE. Another metabolite was detected is suggestively produced by the reduction of the ketone moiety to produce dihydro-MXE or by two steps of O-demethylation and hydroxylation to produce O-desmethyl –hydroxy-MXE. However, due to low intensity signal recorded, MS/MS study was not conclusive for the identity of the molecule In the third part, two types of hepatocytes were used for the study of the metabolism and cytotoxicity of the selected NPS - Mephedrone, Methoxetamine, Methcathinone and 4-Fluoromethamphetamine. Studying the metabolism of selected NPS followed utilizing HepaRG™ followed by GC-MS analysis, it was possible to detect new peaks in the chromatograms of mephedrone and methcathinone which is suggestively the product of N-demethylation. However, it was not possible to detect any new peaks in the chromatograms of methoxetamine nor 4-flouromethamphetamine. The cytotoxicity study utilizing HepaRG cell line showed that these drugs have cytotoxic effects causing in vitro cell death, within the specified range of 4.0x10-2-1.6x101 mM. These drugs were able to cause 43-83% ii cell death, and EC50 values were 0.2323-0.6297 mM. The most potent drug was 4-fluoromethamphetamine, while mephedrone showed the least biological effect to produce.

Attitudes towards sexual offenders have been widely studied in forensic psychology and criminology research over the past 25 years. At present, however, studies examining these views are predominantly descriptive in nature. That is, self-report questionnaire measures are typically distributed to different groups (e.g., general public samples, and members of different occupational categories), with the resultant between-groups differences being reported in research papers. While these studies have provided some interesting findings, the results gained from them fail to inform researchers about the psychological mechanisms that underpin views about this offending population. The overarching aim of this thesis was to begin to fill this knowledge gap. That is, a range of studies were designed to use robust experimental methods, within validated theoretical paradigms, in order to examine some of the potential constructs that influence people’s attitudes towards sexual offenders. Chapter 1 presents a review of the current state of the field in relation to attitudes towards sexual offenders, with gaps in current knowledge being identified. In Chapter 2, the theoretical framework within which the empirical aspects of the thesis operate is set out. Key constructs in this section include dual-process cognition, and our reliance on implicit (i.e., non-conscious) mental processes when making decisions. Chapter 3 builds upon criticisms of one measure of attitudes towards sexual offenders in order to reconceptualise its use into one of an outcome measure. This is then used throughout Chapters 4, 5, and 6 as a measure of sentencing and risk judgements, in order to examine the effects of various experimental manipulations. Studies presented in Chapter 4 found that heuristic-based processes based around the principles of availability appear to influence decision-making about sexual offenders at the macro (political) level, but not at the micro (individual) level. Instead, individual participants’ attitudes and judgements about sexual offenders were dependent on different primes relating to the representativeness (Chapter 5) and affect (Chapter 6) heuristics. Chapter 7 offers a discussion of the empirical findings presented at earlier points of the thesis, and outlines opportunities to develop further work into the heuristic-based nature of attitudes towards sexual offenders. The work contained within this thesis is original, in that well-validated theoretical models are used to begin to examine the psychological mechanisms that may underpin attitudes iii towards sexual offenders. The apparent dual-process nature of such views calls into question some previously-expressed calls within the literature that presenting fact-based information about sexual offenders may lead to improvements in societal attitudes. Instead, it may be that more indirect and emotional methods may be required to achieve such aims. Towards the end of the thesis, clear opportunities for further work are set out, as are some of the potential implications of this research.

Research on crime scene investigation has strongly focused on the technical aspects of the process, while cognitive aspects (searching, reasoning and perception) have often been overlooked. Textbooks on forensic sciences tend to focus on identifying and processing evidence, and the use of equipment while it can be argued that cognitive factors in processing such evidence and using equipment are equally important. This thesis studies the cognitive aspects of crime scene investigation by comparing eye movement patterns in experts and novices. Studies in various domains, including surgery, sports, and chess playing have shown that eye movements differ between experts and novices, providing a tool towards a more objective assessment of skill than is possible with peer assessment. In four experiments eye movements of experts and novices were examined during (1) inspection of photographs of crime scenes on a computer screen (2) a change blindness task on crime and non-crime scene images, (3) active exploration of a simulated crime scene and (4) the assessment of emotional crime and natural scenes. While some trends in eye movement differences, such as a tendency on longer fixation durations and a broader focus on the overall scene and less on the direct evidence could be found in experts compared to novices, differences between experts and novices were considerably smaller than in other domains, despite the broad range of measures extracted from the data. This lack of clear expertise effects may relate to the rather diverse range of perceptual layouts of crime scenes, reducing possible top-down effects of expertise on the deployment of attention. The results will be discussed with a view of possible directions of future research in this domain.