The number of sex offenders repeating their crimes has gone down considerably in England thanks to a pilot program in which the sex offenders were made to undergo polygraph tests.
The government is now arranging to make lie-detector tests for high-risk sex offenders across England and Wales compulsory, following its unprecedented success.
More than 600 sex offenders who were freed on licence were tested every six months in an attempt to find out if they had violated the terms of their release, as part of a study, which was carried out in the East and West Midlands between April 2009 and October 2011.
The study identified that offenders were two to three times more probable to confess to potential breaches of their licence, often before they had even undergone the test procedure.
Those in charge of the study believe the pilot prevented numerous new offences from being committed.
"Successes of course are always invisible, but I have no doubt that a number of offences were prevented in the course of the pilot. On some occasions it's offenders who have been recalled to prison who said if they hadn't been recalled when they were, they would have refunded," Sky News quoted Pilot organizer Professor Don Grubbing, as saying.
Polygraph tests measure blood pressure, heart rate, breathing and levels of perspiration. These vital signs display subtle changes when someone is deliberately evasive and polygraph experts can usually determine if that person is lying, and studies have shown that polygraph tests are accurate around 85% of the time.
An offender can be straight away returned to prison if the lie detector test, coupled with other information, indicates they have broken their licence conditions.
The government is now planning to introduce legislation in parliament to allow the Midlands pilot to be rolled out across England and Wales.