Policy paper

Mandatory polygraph tests factsheet

Updated 3 January 2024

What are we doing?

• provisions in the Domestic Abuse Act 2021 enable the Secretary of State for Justice to impose mandatory polygraph examinations on domestic abuse perpetrators who have been released from prison and identified as being at high risk or very high risk of causing serious harm.

• on 4 July 2021, the Ministry of Justice commenced a three year pilot of mandatory polygraph examinations for eligible individuals released on licence and being supervised within one of four pilot regions of the Probation Service.

• a three year pilot will provide sufficient time to build up the necessary number of individuals subject to polygraph examinations to conduct a robust evaluation. We have commissioned an external body to independently evaluate the pilot.

• at the end of the pilot, the Government will lay a copy of the evaluation report before each House of Parliament. It will use the findings from the pilot to make a final decision regarding wider roll out.

Background

Polygraph examinations have been used successfully by the Probation Service since 2014 in the management of people convicted of sexual offences who have been released on licence . Polygraph tests record an individual’s physiological responses to a small number of targeted questions. These responses include changes in blood pressure, blood flow, respiration rate and sweat responses, which are evaluated to determine whether an individual has responded to questions in a truthful or deceptive manner.

Polygraph examinations are used principally for individuals released on licence to monitor their compliance with other licence conditions. These could include developing new relationships, entering exclusion zones or contact with prohibited individuals. Examinations are also used to monitor dynamic risk factors, such as consumption of alcohol or illegal substances (where related to the individual’s risk of reoffending).

Information obtained during polygraph examinations is used by probation practitioners to refine and improve an individual’s risk management plan, and can also lead to enforcement action.

As head of the Sex Offender Management Unit for Greater Manchester Police, I endorse the use of polygraph testing as a mandatory licence condition by the National Probation Service (NPS) on high risk sex offenders. Under multi-agency public protection arrangements, the information gleaned through polygraph testing by NPS colleagues is shared with the police in order to better manage the risk posed by the individual, where there is joint agency responsibility. There have been a significant number of cases where information gained through polygraph testing has led to children and vulnerable people being safeguarded. Overall, the benefits of polygraph allow our joint resources to better manage the risk posed by registered sex offenders, to concentrate on those who pose the most harm in our communities.

Detective Chief Inspector Jude Holmes, Public Protection and Serious Crime

How are we doing it?

• individuals who meet the eligibility criteria for the pilot and are given the polygraph licence condition will be required to take a polygraph examination within 16 weeks of release from custody. They will then undergo additional testing every six months thereafter unless they return a significant response (commonly referred to as ‘failing’ a polygraph examination). In such circumstances, the individual may be required to undergo more frequent testing.

• we have appointed Probation Officers experienced in the management of high risk offenders to deliver polygraph exams. These Probation Officers have been trained as accredited examiners to the standards set by the American Polygraph Association (APA).

• the Cambridge Centre for Evidence-Based Policing have been commissioned to formally conduct impact and economic evaluations of the pilot. A process evaluation is also being conducted by analysts within the Ministry of Justice. Evaluation findings will be published and laid before Parliament.

• the findings of the pilot will inform decision making about whether to roll out polygraph examinations to this cohort across all probation regions.

Who will be subject to testing?

A polygraph condition will be added to the licences of individuals who are:

• aged 18 years and over.

• assessed as high or very high risk of serious harm using nationally accredited risk assessment tools.

• convicted of one or more eligible domestic abuse-related offences. These include murder; a specified violent offence; breach of a restraining order where the offence involved domestic abuse; or controlling or coercive behaviour in an intimate or family relationship.

• sentenced to a term of custody of 12 months or more for an eligible offence and released on licence into one of the four pilot regions.

Can information from polygraph tests be used in court?

Information from the polygraph cannot be used in criminal courts as evidence against the individual who is subject to testing.

Can individuals be recalled to custody for failing a polygraph examination?

People on supervision subject to a polygraph testing licence condition cannot be recalled to custody solely on the basis of returning a significant response. However, they can be recalled for making disclosures during the examination that reveal they have breached other licence conditions or suggest that their risk has escalated to a level whereby they can no longer be managed safely in the community.

Individuals who return a significant response during their examination will likely be scheduled to undertake a further polygraph examination ahead of their next planned appointment. They may also have further conditions added to their licence.

Information gathered from a polygraph examination may also be shared with the police who are able to conduct further investigations that may or may not result in charges being made.

Individuals who attempt to ‘trick’ the polygraph examination, or who refuse to take it, can be recalled to custody.

Why bother with polygraph examinations if the results cannot be used as evidence in court or as the basis for recalling offenders to prison?

Polygraph examinations are used as an additional source of information for probation practitioners supervising individuals on licence.

There are sanctions for individuals who fail polygraph examinations or make risk-related disclosures during their test. These include increased reporting, the imposition of additional licence conditions or changes to the individual’s risk management plan, such as being directed to reside in approved premises. In addition, probation practitioners can change the focus of an individual’s supervision in order to address any issues that relate to examination questions that returned a significant response.

Are polygraph examinations accurate?

A comprehensive review published by the American Polygraph Association indicated that polygraph is a highly accurate tool that can detect deception in approximately 80-90% of cases (Nelson et al., 2011) ^{[footnote 1]}.

How well has mandatory polygraph testing worked in the Probation Service with people convicted of sexual offences?

There is considerable evidence to demonstrate the efficacy of polygraph testing with people convicted of sexual offences. The use of polygraph for people on probation convicted of sexual offences was trialled from 2009 through a pilot covering the East and West Midlands probation regions. The University of Kent evaluated this pilot between April 2010 and December 2011 (Gannon et al., 2012) ^{[footnote 2]}. The evaluation concluded that polygraph testing increased the likelihood that an individual would disclose information relevant to their management, supervision, treatment or risk assessment. This, in turn, led to an increase in actions taken by probation practitioners to protect the public from harm.

Since 6 January 2014, over 7,000 tests have taken place with individuals convicted of sexual offences, with two-thirds of those tests resulting in significant disclosures.

Is there a risk that probation practitioners will use the polygraph examination as a substitute to for existing risk assessment?

There is no evidence from the use of polygraph examinations with individuals convicted of sexual offences that polygraph is used as a substitute for other forms of risk assessment and management. Polygraph examinations are not intended to replace any other forms of risk assessment or management. Instead, examinations provide probation practitioners with information they would not otherwise have had access to, thus aiding their supervision of individuals who are subject to testing.

Case examples of the use of polygraph with people convicted of sexual offences in the Probation Service

J is a 47-year-old man convicted of the sexual abuse of young boys.

J has a licence condition not to have contact with children under the age of 18 years.

J was subject to mandatory polygraph testing as part of his release conditions following a nine year custodial sentence.

During a polygraph examination, J denied any contact with children under the age of 18 years. This response returned a significant result, indicating possible deception.

The polygraph examiner contacted J’s probation practitioner who immediately contacted the police. The police were waiting for J when he returned to his property and found three young boys and another adult in the house.

J was recalled to custody immediately. The police were then able to make further investigations.

C is a 33-year-old man convicted of downloading and sharing indecent images of children.

C has a licence condition not to possess any internet devices unless approved by his supervising officer.

C was subject to mandatory polygraph as part of his release licence following a three year custodial sentence.

During a polygraph appointment, C disclosed to his examiner that he had a laptop, but that it was his mother’s and not internet enabled. During his exam, the examiner then asked C, “Other than what you have already told me, do you have any internet-enabled devices?” C responded “No”, which elicited a significant response indicating possible deception. After the polygraph examination, the examiner told C about this response and asked him if there was anything he would like to disclose. C said there was not.

The polygraph examiner notified C’s probation practitioner, who visited C at home with the police who had a warrant to search the property.

The police discovered numerous phones, a laptop and several USB sticks containing indecent images of children. C was recalled to custody immediately and charged.

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1. Nelson, R., Handler, M., Krapohl, D., Gougler, M., Shaw, P., & Bierman, L., Ad-hoc Committee on Validated Techniques—American Polygraph Association. (2011). Meta-analytic survey of criterion accuracy of validated polygraph techniques. Polygraph, 40(4). https://www.polygraph.org/meta-analytic_survey_of_criter.php ↩

2. Gannon, T.A, Wood, J., Pina, A., Vasquez, E. & Fraser, I. (2012). The evaluation of the mandatory polygraph pilot. University of Kent. Ministry of Justice Research Series 14/12. https://www.gov.uk/government/publications/the-evaluation-of-the-mandatory-polygraph-pilot ↩