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Online-Issues » 1-2011 » Wilcox & Buschman

Case Studies in the Utility of the Polygraph

Daniel Wilcox1 & Jos Buschman2
1 Wilcox Psychological Associates, Birmingham, UK
2 Legalconnections, Markelo, The Netherlands

[Sexual Offender Treatment, Volume 6 (2011), Issue 1]


The purpose of this presentation is to provide examples of how the polygraph can be used to work more effectively with sexual offenders. The authors describe that the polygraph can offer opportunities to understand the thoughts and behaviours of sex offenders in ways that can inform issues central to the individual's probation or parole conditions. The various case examples used explore multidisciplinary work with the assistance of a polygraphist to, for example, address 'amnesic', as well as more subtle levels of denial, to obtain information associated with additional past offending as well as future risk. They report on an initially challenging offender who, subsequent to making disclosures, reported the belief that this technology was useful for him as a deterrent to engaging in future risky behaviour. The presentation concludes with reflections on these case examples in the monitoring, treating and assessing of sex offenders within the broader context of offender management, rehabilitation, and public protection.

Key words: polygraph, sexual offenders, monitoring, denial


The first author of this manuscript examined the application of the polygraph to specific intervention areas with convicted sex offenders to enhance assessment, focus of specific impediments to treatment and contribute to more comprehensive monitoring and public protection.

This presentation explored experiences in the UK, where the polygraph was voluntarily employed as an adjunct to other established approaches for working with convicted sex offenders. The authors advocated an integrated approach where the polygraph could be employed as an additional external control over the offender's behaviour and as an incentive for convicted sexual offenders to acquire and demonstrate better internal controls over their abusive thoughts and behaviours. It was suggested that in sex offender work the polygraph was, in some ways, analogous to the urinalysis procedure employed in drug monitoring. No one who has a "urinalysis kit" could accurately report having a comprehensive drug treatment programme. However, as with the polygraph, this technology provides a useful tool that may assist in the overall management, treatment and assessment of an offender population.

It was also noted that the polygraph had important utility in the trials conducted in the UK, even though it was administered entirely on a voluntary basis, wherein the convicted offenders could have simply elected not to be polygraphed. In relation to this, the authors would assert, that the aim of any polygraph examination is 'to get the offender to pass', as such a result, based on carefully considered, individualised questions, increases confidence in working with the offender, as well as understanding his offence related thoughts, motivation and behaviour. For this reason a coordinated and integrated approach to employing polygraphy in sex offender work has been found to be most profitable.

The authors explored several case examples, noting that the Sexual History Disclosure Examination (Wilcox, 2000; Wilcox, 2009) consistently provided, additional, hitherto unknown information, about wide ranging deviant sexual interests and behaviours amongst the men polygraphed, even on a single occasion, having been supervised and engaged in formal sexual offender treatment work for many months. The authors expressed the view that the polygraph can also provide a useful role in Risk Screening, though it will be necessary to establish a means of integrating this information into formal, established actuarial and dynamic risk assessment (Gannon, Ward and Beech 2008; Beech, Craig and Brown 2009; Craig and Beech 2009; Gannon, Ward and Beech 2009).

Specifically the authors considered that the polygraph could provide a useful role in gathering information which would otherwise be difficult to obtain in relation to various areas of an offender's life, like employment or relationship status, and offence related personal habits and behaviours (i.e. lifestyle disruption, alcohol or substance misuse). Further, deviant sexual interests associated with aggravating factors in static risk assessment (Hanson and Thornton, 2000), including offences against strangers, underage male victims and non-contact offending behaviours, which can also be examined through the use of polygraphy.

The authors also considered the role of the polygraph in addressing denial issues and dismantling the different types of deception associated with this phenomenon that can act as a barrier to engagement in the great majority of sexual offender group work programmes offered. While it was acknowledged that Hanson and Bussiere (1998) have identified that denial is not a risk factor, it does have an impact upon treatment access as most sex offender intervention programmes provided in the UK and the USA require a degree of acceptance of one's abusive behaviour, if the offender is to be included in a group treatment programme. Further, the authors would contend that this pattern of responding likely relates to some pro-offending cognitive distortions.

Case Studies

An example is given of an offender who was initially describing amnesia with regard to his conviction for sexually assaulting his daughter. This individual reported an acceptance of his guilt but no active knowledge about his offending. He was involved in individual treatment work after completing an induction group work programme from which he was suspended because of significant problems engaging him in this treatment process. The combination of individual sessions offered by a psychologist and periodic employment of polygraph gave rise to initial acceptance of memory of the offence, though he continued to deny any conscious awareness of a sexual interest in his daughter.

The polygraph appeared to play the role of helping the offender to "find the truth" as he described it, in a manner that appeared to have some 'face saving' merit for him. Various layers of denial continued to present through treatment and further polygraph examination, but ultimately this individual openly acknowledged sexual interest in his daughter, both before and after his abuse of her. Notably, however, his final position evidenced a last ditch effort to diminish ownership of his behaviour as he projected blame on to his daughter for not being more vocal in her rejection of his advances (the abuse). In spite of this, over a period of some five months through a combination of individual work and polygraph assistance, this individual moved in his acceptance of his offending to a place where involvement in a standard Sex Offender Groupwork Programme was entirely achievable.

The authors describe a further offender who had been convicted of internet child pornography offences. However subsequent to conviction he vehemently denied any interest in the downloaded indecent images of children, aged 7 to 12. Further, within the groupwork programme, and at the time of his first voluntary polygraph examination, this offender (with a single conviction for a sexual offence) remained adamant, and in the eyes of some individuals working with him, rather convincing in his protestations of innocence. However, this individual failed his polygraph examination, though he made some disclosures of sexual interests in adult pornography and even masturbatory sexual behaviour, engaging in such activities, with other adults, using webcams on the internet. Notably, this offender's viewing of internet child pornography was reported as a result of his neighbour's six year old daughter disclosing this information to her carers. Throughout treatment and initial polygraph testing, this offender denied a sexual interest in indecent images of children. Further, he rejected any notion that he was employing these images as a means of grooming his neighbour's daughter, and he reported that there had never been any risk of him sexually harming her. Notably, he remained adamant in making these assertions and it was agreed that he would be polygraphed again in three months time due to failing his first examination.

However, at the time of this internet offender's second scheduled polygraph examination, he completely reversed the previous assertions made during the aforementioned polygraph examination. This individual now stated that he had intentionally shown the indecent images to his neighbour's daughter, in addition to having fantasised about sexually assaulting her. Further he admitted that he would have likely abused her, had he not been apprehended for downloading the indecent images of children. Following these pre-test disclosures, the offender passed this second polygraph examination, having been honest about issues he had previously categorically denied. Indeed, this offender reported that the polygraph had resulted in an important inhibiting effect on his sexual thoughts and behaviour, and he therefore requested that he be polygraphed again in three months, to ensure that he remained offence-free. Notably, this offender specifically requested that at his next polygraph examination he should be given questions concerning involvement in 'chat rooms'. This individual acknowledged having previously interacted with a female under the age of sixteen via a chat room, and as such considered that this was a particularly risky area for him.

The author's note that previous research presented by them earlier at the 11th IATSO conference in Oslo (Buschman and Wilcox, 2010) had given substantial indication of a pattern of socially desirable responding amongst first time (Dutch) internet offenders. Prior to being polygraphed these offenders generally described naturist and artistic interests in relation to the indecent images they downloaded. Further those offenders who did acknowledge sexual motivations, asserted a primary interest in pubertal teenagers (usually girls in their early to mid teens). However, after being polygraphed, there were indications of a marked "deviant shift" with regard to disclosures made. In general, these reflected strong sexualised interests and inappropriate behaviours towards younger pre-pubertal children, together with notably higher risk behaviours. These included masturbating to thoughts of having sex with children, making plans to do so, and seeking contact with children. Further, a number of actual reports of 'hands-on' sexual offending against children were made by some of these internet offenders who had no documented history of contact sexual offences.

In consideration of the British internet offender in our case presentation we noted marked similarities in terms of the disclosures and risk factors that were elicited with the assistance of polygraph examination. The authors note that the polygraph has been described as an "artificial conscience" (Schmidt, Soloman, and Johnson, 1973), in its role in dissuading offenders from re-engaging in a cycle of offending thoughts and behaviours (Wolf, 1984). They further considered that the polygraph may enhance public protection and assist offenders in treatment to become more open and accountable for their offending behaviour. This may enable more robust and meaningful relapse prevention strategies to be developed between individuals convicted of sexual abuse and their treatment facilitators. This would hopefully result in such offenders achieving a productive and offence-free life in the future.

The authors conclude that the polygraph has shown its utility when employed in an integrated manner alongside the range of assessment, treatment and supervision tools currently being used in working with convicted sexual offenders. As with other areas of sex offender engagement, the authors also supported the continued objective assessment of this technology and registered their support of the UK Government decision via the Offender Management Act (2007) to employ polygraph on a compulsory basis whilst continuing to evaluate its effects and benefits through further designated research.


This presentation was given at the IATSO Conference in Oslo, Norway 4 September 2010. The abstract was reprinted from Langfeldt, T., Hermstad, K., Eher, R., & Marshall William L. (Eds): New Perspectives in Sex Offender Treatment: Restorative Justice, Legal Questions and Humanistic Traditions as Challenges to Therapy, Forensische Psychiatrie und Psychotherapie, Vol. 17 - 2010, Supplement 1, p.106.


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Author address

Daniel Wilcox
Wilcox Psychological Associates
Birmingham, UK
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