Sex offenders must take lie detector test before release

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About 25 sex offenders have been chosen to take part in the tests, which will begin on Wednesday, and between 350 and 450 are expected to be tested over the next three years. Those who refuse risk being sent back to prison.

Each polygraph session will take between 90 minutes and two hours and will consist of three phases. During the pre-test interview the subject will be told the questions they are to be asked so they can make any relevant disclosures beforehand. They will then be attached to the polygraph machine and asked the questions. The operator will interpret the responses and, in a final interview, the subject will be told the results of the test and asked to account for any failures. (PA)