Hertfordshire carries out lie detector study

Hertfordshire Constabulary has been conducting a new study on the usefulness of lie detector tests.

The force is reported to have completed a successful pilot scheme in November in which 25 low-level sex offenders were tested.

Many were exposed as being a higher risk to children than originally thought, The Times newspaper reported, and a further 12-month trial has been approved to begin in April.

Although Devon and Cornwall Police has used a lie detector on a single occasion when investigating a violent crime, the Hertfordshire trial marks the first use of pre-conviction testing in the UK.

Professor Don Grubin, a forensic psychiatrist at Newcastle University, is overseeing the Hertfordshire testing. He said that the psychological pressure of being hooked up to a lie detector often resulted in offenders making disclosures that were unlikely to be made in an ordinary interview room.

The polygraph tests were used to assess the risk posed by sex offenders who were accused of accessing graphic images online.