Despite warnings from Mr Justice Macpherson that the jury should only concern itself with the activities of the officers - not the guilt or innocence of the Four - counsel for the former detectives were determined. One told the jury: 'The innocent Patrick Armstrong (one of the Four) does not exist. He is a being created by the ill-informed, the misinformed, and the not- want-to-be informed.'
These assertions were based upon Mr Armstrong's confession. They had to be. There was and remains no other evidence against Mr Armstrong or the three others who were to become known as the Guildford Four - Gerard Conlon, Carole Richardson and Paul Hill - except confessions.
But while what purported to be their own words was used successfully to convict them in 1975, the dangers and unreliability of uncorroborated confession evidence have since been exposed.
The Four's case at their trial and first unsuccessful appeal was that the confessions were concocted and beaten out of them.
But concerns about the Guildford case go further than simply the admissibility of confession evidence. There was a wealth of information available to the prosecution before the Four's trial - which indicated that the confessions may be false. It was never revealed at their trial or to their lawyers. It included vital alibi and scientific evidence linking the Guildford and Woolwich pub bombings to a series of terrorist 'safe houses'. The safe houses were in turn linked to IRA men - not the Four.
Further, by 1977 and the Four's first failed appeal, terrorists known as the Balcombe Street gang had confessed to the pub bombings. And unlike the Guildford Four, these confessions were supported by scientific evidence. But the gang was never charged with the pub bombings.
There were other strange factors. Carole Richardson had contacted police complaining of an assault a few days before the bombing. 'IRA terrorists are not likely to draw attention to themselves in this way,' Alastair Logan, solicitor for two of the Four, said.
None of these inconsistencies were aired in the trial which ended yesterday. Nor were other problems with the evidence from Surrey police which prompted the Court of Appeal to free the Four in 1989 after 15 years in prison.
At that appeal, Roy Amlot QC, representing the Crown, said that as well as prima-facie questions about evidence in relation to Mr Armstrong's confession, there were similar problems involving the other officers in relation to confessions taken from Mr Hill. Further, there were two sets of custody records for the Four, implying one was false.
The Director of Public Prosecutions decided to charge the three officers in relation to the Armstrong confessions.
At the opening of their trial last month, Julian Bevan, for the prosecution, said deletions, crossings out and handwritten amendments to one set of typed notes indicated that the three officers had lied when they testified on oath that another set of handwritten notes were made contemporaneously as Mr Armstrong confessed. Mr Bevan said the officers' motive in 'manufacturing' evidence was to 'bolster' the case against Mr Armstrong. But this was yesterday unanimously rejected by the jury.
Still, to this day, none of the Guildford Four have seen the evidence which led to their acquittal. 'They waived that right in order for the Surrey officers to have a fair trial,' Mr Conlon's solicitor, Gareth Peirce, said.
There are doubts about whether key questions raised by the case and the part played in it by other people will ever be answered.
Who, in the prosecution team, for example, decided not to disclose that Gerard Conlon, had an alibi for the night on which the Guildford bombings happened?
Who in the Director of Public Prosecutions' office instructed a scientist to alter his evidence?
Why, when IRA members of the convicted Balcombe Street gang admitted their part in the Guildford bombings, was the case not reopened?
Leading article, page 25Reuse content