When trial can lead to error: Paul Hill's return to court raises wider questions for the justice system, says Heather Mills

PAUL HILL, one of the Guildford Four, returned to court yesterday to appeal against his 20-year-old conviction for the murder of a former British soldier, Brian Shaw, in Belfast - and immediately reopened the old Guildford controversy. Hill's confession to the murder came at Guildford police station on the same day he admitted involvement in the 1974 Guildford pub bombings in which five people died.

And yesterday Lord Gifford, his counsel, said he would be relying upon new evidence to support claims that the confessions - the only evidence against the Four - were obtained under duress.

Ever since the extraordinary scenes of jubilation outside the Old Bailey in October 1989, when the Guildford Four walked to freedom after 15 years in jail, the criminal justice system has been trying to claw back its reputation at their expense. From low-ranking policeman to senior politicians, the whispered word has been that the convictions of Hill, Gerry Conlon, Carole Richardson, and Patrick Armstrong were quashed on a mere 'technicality' and that there was no miscarriage of justice.

It is true that at their 1989 appeal the Four's conviction was quashed on the narrowest of grounds: five Surrey police officers appeared to have doctored two confession statements and lied at their trial. Because the prosecution capitulated in the face of that evidence, the appeal court, unusually, decided not to hear a wealth of other material pointing to the innocence of the four young people.

Just three of the most worrying aspects were, first, that the case was not reopened more than 13 years ago, when the Balcombe Street IRA gang admitted to the Guildford bombing; that Conlon had an alibi which the prosecution had not disclosed; and that a government scientist had been instructed by someone in the office of the Director of Public Prosecutions to alter his evidence relating to the Balcombe gang, so as not to weaken the prosecution case against the Four.

By the time it came to bring criminal charges in response to the injustice that befell the Guildford Four, however, just three Surrey officers were left to carry the can. They were accused of conspiracy to pervert the course of justice by having doctored interview notes relating to Armstrong. The officers' trial, last April, at which they were acquitted, seemed to become a retrial of the Four. The officers chose not to give evidence, leaving their lawyer to claim that Armstrong 'had sung like a canary'.

But yesterday in Belfast, Lord Gifford indicated that it was not simply over Armstrong's interviews that there had been suggestions of police malpractice. There was, he said, evidence that 10 of the 13 Surrey officers involved in the interviews had been guilty of serious impropriety in the rewriting of handwritten notes and the presentation of them as contemporaneous.

More significantly, he said that new evidence supported claims by the Four that their confessions were extracted under duress. There was now testimony 'that a firearms officer had been seen to point a gun through the hatch of a cell at Guildford police station and had been heard subsequently to boast of his deed'. Hill had claimed police staged a mock execution by poking a gun through the bars of his cell.

The new evidence was uncovered by Avon and Somerset police, who were first called in to investigate the Guildford Four affair in 1987 after a powerful delegation led by Cardinal Hume and Lord Scarman persuaded the then Home Secretary, Douglas Hurd, that there were strong grounds to believe the Four were innocent.

The Avon and Somerset material has apparently been passed to Sir John May, who for the past four and a half years has been conducting an inquiry into the Guildford Four case and the related case of the Maguire family. But even the May inquiry may fail to shed much further light on the case.

Although the May inquiry interim report, following public hearings into the Maguire case, had severely criticised judges, prosecutors and government scientists for their role in the miscarriage of justice, the Guildford part has been held entirely in secret. Without powers to subpoena witnesses or compel the disclosure of documents - and without public pressure for those involved to account for their actions - the suspicion is that Sir John's inquiry has become a paper exercise.

Chris Mullin, the Labour MP who campaigned to overturn the Birmingham Six, Guildford and Maguire convictions, said he believed Sir John's inquiry had 'been knobbled from the moment that it became clear that he was not prepared to participate in a whitewash'.

Sir John is due to report to ministers in the next few weeks. But it remains an unhappy fact that without yesterday's Belfast court hearing, new evidence - some of which has been known about since 1990 - may have remained under wraps for ever.

The reason is that information gathered in such police investigations is only available to the prosecuting authorities - and if they choose not to act upon it then it remains confidential, even from those most affected. In this case it is the Guildford Four. But similar anxieties were raised only last week in the case of Joy Gardner, the Jamaican woman who collapsed and died seven months ago after a struggle with immigration officers.

If it is decided that there is insufficient evidence to charge or bring disciplinary action against the officers, the files will remain closed, and Mrs Gardner's family, and indeed the public, will never know exactly what happened.

The Government has said it is committed to setting up an independent body to investigate miscarriages of justice. One of its first tasks must be to widen the scope of the police investigations - often closely focused criminal inquiries rather than searches for the wider picture - and to ensure that new evidence is disclosed, even where it is declared insufficient to act upon. At the same time ministers are also considering proposals to allow the prosecuting authorities the right not to disclose material considered 'sensitive' - which, if abused, can lead to more injustice.

It may be that the powerful film of the Guildford Four and Maguire Seven's story, In the Name of the Father - even with its well-publicised inaccuracies - is pushing home far more effectively than the legal process the message that these 11 people suffered a monstrous injustice.

But that is not how it should be. In the absence of a better remedy, it is now down to you, Sir John.

(Photograph omitted)