Home affairs editor Alan Travis reports for the Guardian.
Home Office plans to introduce compulsory lie detector tests to ensure that convicted paedophiles do not offend again are worrying cabinet members.
The home secretary, David Blunkett, has admitted to his cabinet colleagues that the plans “are not without controversy” and is seeking legal clearance from Lord Goldsmith, the attorney general.
A leaked ministerial letter dated July 20 shows that Patricia Hewitt, the trade and industry secretary, a former head of the National Council for Civil Liberties, wants “further evidence” before a decision is reached this summer to push ahead with the necessary legislation.
Mr Blunkett has asked the cabinet to approve the plan, describing the polygraph tests as “an additional weapon in the armoury against sex offenders”.
When the Guardian disclosed the scheme in May the human rights organisation Liberty, the NCCL’s successor, said it would raise no fundamental objections as long as the results were not used in court as evidence and would help prevent reoffending.
The shadow home secretary, David Davis, has also said their use could be beneficial.
The American polygraph technology is being considered alongside the introduction of satellite tracking of convicted sex offenders to monitor their behaviour after their release on licence from prison.
A voluntary two-year trial in 12 of the 42 probation areas, including Northumbria, the West Midlands and Sussex, is understood to have been judged a success. It has involved 120 convicted sex offenders, who have been tested every six months.
Five polygraph machines have been used in the trials. They measure changes in breathing, heart rate and sweat in response to questioning, and officials believe they can be used to establish, along with other evidence, whether convicted sex offenders are telling the truth about whether they have been trying to contact children.
“We’re not talking about a countrywide expansion of the scheme,” a Home Office spokeswoman said yesterday.
“What we’re looking for now is to make these pilots mandatory so that we can fully assess the effectiveness of lie detector tests in helping to monitor sex offenders and ensure the safety of the public.”
She stressed that the tests would not be used to gather evidence admissible in court, which is the source of much of the controversy surrounding their use in the US.
Nor will anybody be sent back to prison solely on the evidence of the results of a polygraph tests. “They are being used only as a limited management tool to support a range of other methods employed to monitor and supervise sex offenders,” the spokeswoman said.
Mr Blunkett has acknowledged the controversial nature of lie detector tests before.
“We are all a bit sceptical, because we’ve all been brought up with the spy films and the way in which the KGB are allegedly able to train people to avoid them. But we are talking about really modern technology in the 21st century, and we are testing it,” he said when he launched the idea in June.
“It won’t only just pick up whether a person is lying, it will also be a major deterrent to people actually telling an untruth when they are under supervision and when it is necessary to find out what they’ve been up to.”