The Utility of Polygraph with Mentally Disordered Sex Offenders by Nikki
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View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Birmingham Research Archive, E-theses Repository The Utility of Polygraph With Mentally Disordered Sex Offenders by Nikki Collins Thesis submitted to the University of Birmingham for the degree of Doctorate in Forensic Psychology in Practice (ForenPsyD) The Centre for Forensic and Criminological Psychology University of Birmingham March 2019 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Abstract The use of post-conviction polygraph testing with sex offenders is used worldwide. However, to date there is no known study that has examined the utility of polygraph with mentally disordered sex offenders, which is the focus of this current thesis. An introduction to polygraph outlines how the tool works, the three test types and the suggested psychological theories, that attempt to explain the psychophysiological responses observed in polygraphy. Chapter 2 is a systematic literature review of the utility of polygraph post-conviction sex offender tests (PCSOT) with sex offenders in general, focussing on the areas of assessment, treatment and management. The review highlights key findings relating to recidivism, risk, disclosures, polygraph outcome and perceptions of the polygraph. Further to this, the review suggests that polygraph enhances the assessment of sexual offenders by leading to increased disclosures (victims, offences and sexual risk behaviours). Additionally, this thesis introduces the Violence Risk Scale, Sex Offender version (VRS-SO) as a sexual risk assessment tool. A critique of this assessment considers the reliability and validity of the tool. The VRS-SO is used in the empirical study of this thesis, which investigates the use of polygraph with mentally disordered sex offenders in a high secure forensic setting. The key significant findings are that using polygraph with mentally disordered sex offenders was effective in eliciting more information about behaviours associated with risk. Specifically, eliciting an increase in the number of high risk behaviours; a broader range of paraphilic behaviours; the number of victims; the number of inappropriate sexual fantasies; the reported level of masturbation to inappropriate sexual fantasies and the use of pornography. Offenders were also asked about their experience of polygraph. Thematic analysis of their responses suggested four main themes of risk, truthfulness, impact and knowledge. Finally, implications of this thesis are considered in addition to future research into the utility of polygraph. Acknowledgements I extend my thanks to Professor Tony Beech who started the journey with me to undertake this thesis, and huge gratitude goes to Dr Caroline Oliver who picked up the mantle and was “that” supervisor who helped me over the finish line. Your encouragement and feedback was greatly appreciated. I honestly do not know if I would have done this without you. I thank my colleagues at work, particularly James Tapp for the stats advice, Karen for your help and support, Nicola T for always being there and supporting me through some challenging times, and Estelle for spurring me on in the final stages with lovely quotes and late night cheerleading messages. To my friend Naz for always believing in me. To my fellow school governors and ever caring Head Mistress Mrs Lynch for their understanding when I needed space to focus on my studies, and checking in with me. Finally but most importantly, I am eternally grateful to my parents for encouraging my studies all along and inspiring me to always achieve more. To my husband, Christian for supporting me through some very challenging times and our beautiful children, Orlaith and Emilia, to whom I owe much more of my time to now. Contents Page List of tables …………………………………………………………. i List of Figures …………………………………………………………. iii List of Appendices …………………………………………………………. iv Chapter 1: Introduction…………………………………………………….. - Polygraph Tool……………………………….……….. 1 - Theoretical underpinnings of polygraph ……………... 6 - Criticisms of polygraph ……………………………... 9 - Post-conviction sex offender testing (PCSOT) polygraph ……………………………………………... 13 - Justification for thesis ……………………………….. 20 - Overview …………………………………………….. 21 Chapter 2: The utility of polygraph with sexual offenders - a systematic Review ………………………………………………………….. - Abstract….. …………………………………………... 23 - Background …………………………………………... 24 - Method ……………………………………………….. 37 - Data extraction …..…………………………………... 45 - Results ……………………………………………….. 46 Descriptive data synthesis …………………........... 56 Assessment and treatment of sex offenders ………. 58 Management of sex offenders …………………… 61 - Discussion …………………………………................. 75 Limitations …………………………………... 79 Conclusions and recommendations ………….. 82 Chapter 3: Polygraph with mentally disordered offenders: The utility of post-conviction sex offender testing (PCSOT) in a secure hospital …………………………………………………………. - Abstract .………………………………........................ 84 - Introduction ………………………………………….. 85 Polygraph and mental health …...…………….. 88 Research aims………………………………..... 92 - Method ……………………………………………….. 93 Participants ………………………………….... 93 Materials …………………………………….... 96 Ethics ………………………………………..... 101 i Quantitative procedure………………………... 102 Qualitative procedure ………………………... 103 - Results ……………………………………………….. 105 Quantitative Analysis ……………………….... 108 Qualitative Analysis ………………………….. 115 - Discussion ………………………………….................. 126 Limitations ……..……………………………... 133 Conclusion ..…………………………………... 135 Chapter 4: Critique of the Violence Risk Scale-Sexual Offender version (VRS-SO) ……………………………………………………………………. - Introduction ………………………………………….. 138 - Description of assessment …………………................. 139 - Level of measurement ……………………………….. 141 - Reliability …………………………………………….. 141 - Validity ……………………………………………….. 143 - Normative data ……………………………………….. 152 - Conclusion …………………………………................. 153 Chapter 5: Discussion ………………………………………………………. - Summary of findings ………………………................. 157 - Practical and theoretical implications ………………… 160 - Strengths and limitations ..……………………………. 162 - Further research ……………………………………..... 162 References …………………………………………………………………… 164 Appendices ………………………………………………………………….. 177 ii List of Tables Page Table 1. Characteristics of quantitative studies examining utility of 47 polygraph with sexual offenders Table 2. Characteristics of qualitative studies examining utility of 55 polygraph with sexual offenders Table 3. Synthesised evidence of studies on the utility of PCSOT 67 and grouped by outcome measure Table 4. Number of individuals that made admissions during a 107 polygraph and outcome data Table 5. Number of disclosures reported pre, during and post- 110 polygraph Table 6. Pre to post polygraph reporting of sexual behaviour 111 Table 7. Victim age and gender reported at file and during 112 polygraph Table 8. Victim age and gender reported at file and during 112 polygraph VRS-SO data Table 9. VRS-SO data Polygraph outcome according to risk 114 category on the RM2000/S iii Table 10. Polygraph outcome according to risk category on the 114 VRS-SO Table 11. Themes and Sub-themes identified from thematic analysis 115 for polygraph and no-polygraph groups Table 12. Main themes and sub-themes identified from thematic 116 analysis Table 13. AUC and Cohen’s d effect size comparisons 145 iv List of Figures Page Figure 1. Flowchart of study selection process 42 Figure 2. Total number in each VRS-SO risk category 113 Figure 3. Total number in each RM2000/S risk category 113 v List of Appendices Page Appendix A Papers based on full text 178 Appendix B Quality assessment form for quantitative studies 180 Appendix C Quality assessment form for qualitative studies 182 Appendix D Quality assessment scores for final papers reviewed 185 Appendix E Quality assessment of included quantitative studies 188 Appendix F Quality assessment of included qualitative studies 197 Appendix G Data extraction form 199 Appendix H Study information sheet and consent form 202 Appendix I Semi-structured interview schedules 210 Appendix J List of sexual behaviours recorded in data collection 213 Appendix K Risk Matrix 2000/ Sexual score sheet 214 Appendix L Violence Risk Scale Sex Offender version score sheet 216 vi Chapter 1 Introduction Polygraph Tool For many years, polygraph has been referred to as a ‘lie detector’. More recently in the UK, however, it has been cited as a ‘truth facilitator’ (Grubin, 2003; Wilcox and Gray, 2012). It is used widely in the United States, where polygraph was first developed, to aid in detecting deception in criminal cases (Synnott, Dietzel & Ioannou, 2015). Other uses have included employment screening, post-conviction sex offender testing, and more recently domestic violence, with a proposed domestic-abuse bill anticipated in the UK in 2020 to include the use of mandatory polygraph (Grierson, 2019). The polygraph was reportedly used