The Rachel Nickell case: Lawyers criticise judge's final say on confessions: Acquittal brings calls for clearer rules on dealing with police 'entrapment' evidence James Cusick reports

THE ENGLISH legal system's reliance on judges to decide the admissibility of confessions obtained during undercover police operations was described as unsatisfactory by leading criminal lawyers.

The freeing of Colin Stagg at the Old Bailey on Wednesday reopens the debate over whether the rules that judges use when deciding to allow or disallow evidence obtained during undercover interviews needs to be clarified.

According to Nicholas Price QC, vice-chairman of the Legal Services Committee of the Bar Council, reliance on judicial discretion is 'unsatisfactory'.

Although the Stagg case has been referred to as 'entrapment' by Scotland Yard's SO10 specialist operations department, the precise legal definition of entrapment is to entice a person into committing a crime in order to secure a conviction.

However, Scotland Yard was investigating a murder that had already been committed. The target of the undercover operation was to lure their prime suspect, Mr Stagg, into making a confession that he killed Rachel Nickell.

Richard Ferguson QC, chairman of the Criminal Bar, said that, in similar situations, police had resorted to placing fellow prisoners in the cells of the accused in the hope of extracting confessions.

Mr Ferguson represented the boxer Terry Marsh, accused, but later cleared, of shooting the promoter Frank Warren. In that case the police had primed the prisoner to get evidence from Mr Marsh.

'There is a line of thought that says if evidence is relevant, it matters not how it was obtained, and can be admitted at a trial,' said Mr Ferguson. But the trial judge has the final say.

Although parallels have been drawn with police attempts to trap drug-dealers in the US, the real question relating to Mr Stagg was the 'reliability of evidence'.

Mr Ferguson said he was 'astonished' the Stagg case ever reached the Old Bailey and that there had been an error of judgement by the Crown Prosecution Service. He said the judge had taken the right decision but another judge might have taken a different view.

Michael Zander, Professor of Law at the London School of Economics, said the Police and Criminal Evidence Act 1984 and its codes of practice were designed to ensure that confessions were not obtained by oppression or by means rendering a confession unreliable.

Undercover operations can only be used if they are consistent with these fundamental rules. But in ruling against the prosecution case, Mr Justice Ognall was applying Section 28 of the Act: if the case had gone ahead, the proceedings against Mr Stagg would have been unfair.

Mr Price said a law allowing entrapment as a defence, as is the case in the US, would unmuddy the English legal waters. The police would know the parameters they were expected to operate within. He added that relying on a judge to rule on the admissibility of such evidence was unsatisfactory.