My Lords, I wish either that this group had been grouped with the previous group or that I had spoken in the previous group, as we seem to be going over the same ground. Can I also push my luck, at the invitation of the noble and learned Lord, as an out and proud non-lawyer and wonder out loud whether lawyers feel somewhat threatened that there might be a machine more able to tease out whether someone is telling the truth or not, or even to tease out a disclosure, than a lawyer? I do not believe lawyers need to worry. I feel this group and the previous one turned into an extension of the teach-in. But I shall press on.
Amendment 20, moved by the noble and learned Lord, Lord Falconer of Thoroton, to which my noble friend has added her name, calls for a review of
polygraph testing on terrorist offenders based on a pilot scheme. I take a slightly different view to my noble friends Lady Hamwee and Lord Marks, probably because they are pure Liberal Democrats, unlike me, who am contaminated by 30 years’ experience as a police officer.
Yesterday, in discussion on the use of polygraph testing in the Domestic Abuse Bill, the Minister talked about how polygraph tests were used. I join other noble Lords in saying how helpful the teach-in on polygraph testing provided by the Ministry of Justice was, and I thank the ministry for it. In that presentation, if I recall correctly, we were told that the tests are 80% to 90% accurate, on the basis of tests carried out on sex offenders. The tests measure physiological changes that occur if someone is trying to think of a wrong answer about an experience they have had in the past. People usually instinctively think of the truthful answer before they offer a dishonest alternative, and this produces physiological changes that the tests pick up. The evidence suggests a dishonest response cannot be used in court, and it is not used to recall someone to prison, but it might prompt further investigation by the police. Failing the test is not a replacement for any other form of risk assessment.
From the notes I made at the time, which take me back to giving evidence in court as a police officer, polygraph tests also prompt disclosures that might not otherwise occur. If such a disclosure indicates the subject has breached their licence conditions or is a threat to the public, this can result in prison recall. In short, disclosures can result in immediate sanction, but failing the test can only lead to further investigation.
Although polygraph tests have been used on a large number of sex offenders and have, therefore, been thoroughly evaluated, it will be more difficult, even with a pilot, to evaluate use with terrorists, as there are far fewer of them. My noble friend Lord Thomas of Gresford mentioned the right to silence, recalling what we were told in the teach-in. The difference here is that these are convicted offenders on licence, who have no right to silence. However, the science is the same whether we are dealing with sex offenders or terrorists, and polygraph tests are useful where there is a pattern of behaviour rather than a single act. It is, therefore, anticipated that their use in terrorism cases will be similarly effective. There has already been considerable experience of using polygraph tests and evaluating the results, somewhat at odds with the comments of the noble and learned Lord, Lord Woolf. But in agreeing with the noble and learned Lord, I think that it is true to say there has been very limited, if any, experience of using polygraph tests in connection with terrorism offences.
I feel sure that the Government will use polygraph testing with terrorists and, as we will hear in a later group, those subject to TPIMs, on a trial basis, as they intend to do in relation to domestic abuse. But the opportunities to evaluate their effectiveness with terrorists will be more limited, because, as I said, the numbers are considerably smaller. I am sure the Minister will say whether I got that right.