One of Britain's most senior police officers has said that witnesses feel so "mucked about" by the court system that they are refusing to attend court again and give evidence in future trials.
Ian Blair, the deputy commissioner of the Metropolitan police, said it was "awful" that witnesses were restricted in the evidence they could present to jurors.
He called on judges to allow juries as much access as possible to the previous convictions of defendants, even during rape trials.
"We need inclusivity of evidence - if the jury is the light by which freedom shines why don't we tell them the truth and allow them as adults to weigh that truth?" Mr Blair said in an interview with the Independent on Sunday.
David Blunkett, the Home Secretary, has drawn up new laws that would allow judges in some circumstances to tell jurors about previous convictions as well as allowing people to be tried more than once for the same crime. But these moves have been condemned by human rights organisations, MPs and legal experts on the grounds that they will undermine the right of defendants to a fair trial by prejudicing their case.
This concern is backed by a study carried out by Birmingham University which showed that juries are biased by learning of previous convictions for similar offences.
However, Mr Blair said it was "blazing nonsense" for a court not to be allowed to retry a defendant for the same crime where scientific evidence was available to prove the person is a criminal.
"If the jury is so important that we must not have judge-only trials then why don't we tell them the truth rather than some extraordinary version in which the most significant pieces are cut out?" Mr Blair asked. He said that in one recent case in North Wales a defendant had been cleared of theft despite having 247 previous convictions for similar offences.
He said that he was asking for juries to be told of "similar and recent" convictions and for juries and magistrates to be given clear guidance on how to proceed. "If someone has been convicted of rape before, then it's relevant to his behaviour," he said.
Mr Blair added that the Met has been particularly successful in combating street crime, which has fallen by 16 per cent. However, he admitted it would be "hugely difficult" to meet the Met's current target which is to recruit more than 25 per cent of its officers from ethnic minority backgrounds by 2009.Reuse content