Forensic Psychology Centre & Polygraphy
The FPC’s polygraph services are primarily for lawyers and government agencies. The most commonly requested uses are for criminal matters and to monitor convicted sex offenders.
The polygraph, or more commonly known as a ‘lie detector’, is used as an investigative technique which forms one part of an overall investigation. It is not our policy to implement polygraphy in isolation. We take instructions regarding private individual cases only through a legal representative, although exceptions can be made on a case by case basis. Disputes between intimates does not fall within our operational scope.
Our examiner is a full member of the American Polygraph Association and based in Brisbane. Our examiner has specific greatest experience in the use of polygraphy with convicted sex offenders and was involved in a major study involving the implementation of polygraphy in the United Kingdom. She has presented at international conferences and published articles within peer-reviewed journals on the use of polygraphy with sex offenders.
Polygraph testing of convicted sex offenders has two main aims: to enhance treatment and to improve supervision. In terms of the former, it is claimed that polygraphy provides fuller and more accurate information about an offender’s history, paraphilic interests and offence behaviour, enabling treatment needs to be better identified and targeted.
In respect of supervision, polygraphy is used to assist in monitoring behaviour and adherence to relapse-prevention plans, with supporters arguing that it both acts as a deterrent to reoffending and aids in the detection of reoffending when it occurs.
A typical polygraph test will take between 2 1/2 to 4 hours and involves a comprehensive interview around the issues that are to be investigated. After the test is completed a report is completed detailing the outcome of the testing process.
It is a requirement of the FPC that all polygraph tests are video recorded.
What is a Polygraph?
The polygraph instrument consists of a physiological recorder which typically assesses three aspects of autonomic arousal: heart rate/blood pressure, respiration and skin conductivity-sweat gland activity.
At the FPC these measures are recorded electronically using a computerized system. The rate and depth of respiration is measured by two pneumographs which are surround the examinee's upper and lower chest. The skin conductivity is measured through electrodes placed on the fingers of one hand. Cardiovascular activity is measured directly by either a blood pressure cuff or a finger-cuff assembly. The fingercuff is a recent development and affords more comfort to the examinee when prolonged assessments are required. Skin temperature can also be recorded which appears to be correlated with autonomic arousal and deception. Changes in these physiological functions are involuntary and are the result of emotional stress; thus by monitoring these bodily responses, any changes that occur as a reaction to questioning can be observed.
The examinations at FPC are conducted in a quiet room, free from any distractions or outside noise. Only the examiner and the examinee are allowed in the testing area and the whole session is recorded both with video and audio.
Peer reviewed publications related to polygraphy from FPC members
Madsen, L. & Grubin, D. (2009). An investigation of the accuracy of community based polygraphy testing with community based sex offenders. Submitted for publication.
Grubin, D. & Madsen, L. (2006). Accuracy and utility of post-conviction polygraph testing of sex offenders. British Journal of Psychiatry, 188, 479 –483.
Madsen, L., Parsons, S. & Grubin, D. (2006). A comparison of DSM-IV Personality disorders and the Five Factor Model in a sample of child molesters. Journal of Personality and Individual Differences, 40, 227 – 236.
Grubin, D. & Madsen, L. (2005). Lie detection and the polygraph: A historical review. Journal of Forensic Psychiatry and Psychology, 16, 357 –369.
Madsen, L., Parsons, S. & Grubin, D. (2004). A preliminary study of the contribution of periodic polygraph testing to the treatment and supervision of sex offenders. British Journal of Forensic Psychiatry and Psychology, 15 (4), 682 – 695.
Grubin, D., Madsen, L., Parsons, S., Sosnowski, D. & Warberg, B. (2004). A prospective study of the impact of polygraphy on high risk behaviors in adult sex offenders. Sexual Abuse: A Journal of Research and Treatment, 16 (3), 209 – 222.
Invited chapters
Whittingham, D. (2009). The Clinical use of the polygraphy with sex offenders: Caveats and considerations (Chapter 2). In Wilcox, D. (Ed). The Use of Polygraph in Assessing, Treating and Supervising Sex Offenders: Practitioner’s Guide: Wiley.
Wilcox, D. & Madsen, L. (2009). Pre-conviction and post-conviction polygraph testing: A brief history (Chapter 3). In Wilcox, D. (Ed). The Use of the Polygraph in Assessing, Treating and Supervising Sex Offenders: Practitioner's Guide: Wiley.
Madsen, L. & Wilcox, D. (2009). The empirical evidence for the value of post-conviction polygraph in the treatment and supervision of sex offenders. In Wilcox, D. (Ed.). The Use of the Polygraph in Assessing, Treating and Supervising Sex Offenders: Practitioner's Guide: Wiley.
Madsen, L. (2009). The accuracy of polygraphy in the treatment and supervision of sex offenders. In Wilcox, D. (Ed.). The Use of the Polygraph in Assessing, Treating and Supervising Sex Offenders: Practitioner's Guide: Wiley.
Addison, S. & Crisilla, L. (2009). Other post-conviction applications of polygraphy. In Wilcox, D. (Ed.). The Use of the Polygraph in Assessing, Treating and Supervising Sex Offenders: Practitioner's Guide: Wiley.