Since January this year Norfolk Police have been offering sex offenders lie detector tests in the risk assessment process.  So successful has it been that there is now a possibility of using the test results for court evidence. Polygraph examinations may also be implemented for assessment of police personnel.

Having purchased polygraph equipment, Norfolk Police now have 3 fully APA (American Polygraph Association) trained staff members.  4 other police forces use lie detector tests in Britain but Norfolk has embraced the technology more actively.

New polygraph study imminent

According to the force research being carried out at Kent University, which will be available this month, could potentially lead to results being used as evidence in court.

So far 116 sex offenders in Norfolk have taken lie detector tests with 65 refusing to do so.  Those that refuse may be deemed higher in risk.

Polygraph metrics

During a polygraph examination there is a pre-test interview between the subject and the examiner. This interview allows the subject to relax and be informed about the questions that will be asked. The examiner explains how the polygraph works and what it will measure.

Included in the metrics are changes in respiration, perspiration, heart rate, and blood pressure.  Lies (or deceptive responses) have an effect on these physiological responses when compared to truthful answers.

Whilst tests are not 100 percent accurate, a fully trained, APA accredited examiner will attain optimum accuracy by analysing the results and having them peer reviewed. Some courts in Europe accept polygraph evidence as to some tribunals when corroborated by other evidence.

There is a general misunderstanding about the polygraph as can be evidenced by misinformation and opinion on the internet.  The equipment is an investigative tool to add to the many detectives possess.  Deceptive answers identified by the polygraph lead to further investigation, often in areas that have not been previously considered.

Lie detector tests in the risk assessment process

Norfolk police are not using the polygraph to establish guilt or innocence. Its application is to assess and manage potential risk of sex offenders.  There are many other options, in addition to lie detector tests in the risk assessment process, available to the police.

We, as polygraph experts, welcome this decision by Norfolk police. Sex offender risk management is paramount in protecting our children.  According to Norfolk Constabulary’s Detective Chief Superintendent Christopher Balmer, there have already been 9 cases which due to “direct positive interventions have safeguarded children.”  Polygraph results from these tests apparently have led to disclosure of sex offenders’ previous convictions.  This allows their associates to be better informed.

It’s great to see that police forces in the UK are appreciating the benefits of lie detector tests in the risk assessment process and are considering other ways in which to utilise them for other risk management issues.