The case was referred by the CCRC to the Court of Appeal in July 1997. The appeal court quashed the conviction on 17 December 1998, ruling that the verdict was unsafe because there had been a failure to disclose relevant evidence.

In addition to the two articles following the quashing of the conviction reprinted here, see also in-depth articles on the Danny McNamee case at Scandals In Justice

The "Hyde Park bomber" has become a landmark for British justice, reports Bob Woffinden

Scant attention was devoted last month to the successful outcome of the appeal of Danny McNamee, known as the "Hyde Park bomber". In publicity terms, McNamee was doubly disadvantaged: not only was the judgment overshadowed by pre-Christmas festivities, it was also given on a day when the news agenda was focused on Baghdad. With Britain and the US dropping so many bombs on Iraq, who was interested in a man who, we belatedly learnt, hadn't bombed anyone at all?

Yet the judgment was of immense importance, for it offered yet another proof of how catastrophically flawed the British justice can be; and because the appeal judges fundamentally restated the legal position with regard to appeals.

McNamee had supposedly manufactured the bomb that exploded in July 1982, killing four soldiers and seven horses.

The Crown's case rested on three fingerprints: one each on short lengths of insulating tape in two caches of explosives-making equipment discovered in Pangbourne and Salcey forests, and a thumbprint on a Duracell battery recovered from the debris after a controlled explosion in Kensington.

As a result, the Crown argued that the "artwork" used in the manufacture of circuit boards found in these locations was so similar that they were all made by "the same original master". This, they asserted, was McNamee. This evidence, together with all the emotive associations of the Hyde Park bombing, added up to a formidable case.

From the outset, McNamee's defence was that, although he was at a loss to explain the thumbprint, there was an innocent explanation for the first two fingerprints. After graduating from Queen's University, Belfast, he was employed by Kimballs in Dundalk, making circuits for gaming machines. If bomb-making had been going on, he was unaware of it. The judge, however, claimed that "two prints . . . could have an innocent explanation; but three prints is beyond coincidence."

The appeal judges noted that the case which they heard in 1998 was very different to that presented to the jury in 1987. It certainly was. The Crown now had to concede that they were unable to say that McNamee was "the Hyde Park bomber" or that he was responsible for the manufacture of the circuit boards. The critical thumbprint, found on the Kensington bomb, also disappeared. A print is supposed to have 16 identifying features, yet of the 14 fingerprint experts called to this appeal, none could now find more than 11 characteristics.

The judges further remarked on the extraordinary amount of relevant material that was not disclosed in 1987. They referred to two "detailed and impressive" reports on the caches of explosives prepared by the anti-terrorist branch of New Scotland Yard. They wrote that, with regard to the cache of explosives found in Pangbourne forest, "the evidence against the bomb-making team of Hughes, Ellis, Leonard and McGuire is overwhelming". The second report said that "Moyna and Harford [are] clearly . . . responsible for the production of the majority of the bomb components found in Salcey forest".

The names are all those of known terrorists. While they were in top-secret reports, McNamee's name was conspicuous by its absence. The defence didn't realise this, however, as no one was thoughtful enough to pass on such vital information. Nor had anyone from the prosecution side bothered to inform them that, although they had found a solitary fingerprint of McNamee's in the Pangbourne forest cache, they had found 24 identified as those of Desmond Ellis, a leading bomb-maker.

Despite all this, the judges still held to the view that McNamee might be guilty. They may have been influenced by a public interest immunity (PII) hearing at the very start of the appeal. One member of McNamee's team explained that the material appeared to consist of "really objectionable low-grade gossip, with the RUC saying they had sightings of McNamee on dates when he was actually in prison". This "evidence" was unchallenged and unchallengeable. (The use in British courts of PII hearings is on the agenda for the European Court, on the grounds that it breaches the right to a fair and public hearing.)

The judges' perspective could have presented serious difficulties for McNamee. One of the provisions of the 1995 Criminal Appeal Act was to change the grounds on which appeals would be allowed from "unsafe and unsatisfactory" simply to "unsafe". Had parliament, in introducing the change, intended a fundamental shift in the court's approach?

The answer, initially determined in the appeal of R v Chalkley and Jeffries, was the latter: appeals were allowed only if judges were convinced the whole case was "unsafe".

Yet McNamee's defence team (headed by the solicitor Gareth Pierce and the QC Michael Mansfield) succeeded in persuading the judges that, for the previous two years, the appeal court had been frustrating the wishes of parliament. The judges conceded, in effect, that the Chalkley and Jeffries judgment was too sweeping and that a real test for an appeal should be "[where] the impact of the fresh evidence on a case is not conclusive, but is such as to render the verdict of the jury unsafe because a tribunal of fact might . . . be left with a reasonable doubt as to guilt".

The appeal means a big step forward for all future appellants. Immediate beneficiaries were Michael O'Brien, Ellis Sherwood and Darren Hall, convicted in the so-called Cardiff newsagent case. Their case was referred to appeal, and the three were released on bail in time for Christmas.

Bob Woffinden asks why standards for fingerprinting are being abolished despite the recent McNamee appeal

For over a decade, it had been the fingerprint community's most contentious exhibit. Was the thumbprint at the top of a Duracell battery that of Danny McNamee, the alleged Hyde Park bomber, or not? According to the testimony of Metropolitan Police experts at his 1987 trial, it certainly was. This being the critical piece of evidence, McNamee was convicted and sentenced to life imprisonment.

In the interim, however, serious doubts developed. The issue was finally thrashed out at his appeal last month. 'We were persuaded to call no less than 14 fingerprint experts,' explained the appeal court judges. 'We heard evidence in relation to this single thumb print over seven full court days. Remarkably, and worryingly, save for those who said the print was unreadable, there was no unanimity between them, and very substantial areas of disagreement.' Peter Swann, generally regarded as the doyen of British fingerprint experts, first saw the print on the day before McNamee's original appeal in 1991. His views have never wavered. 'The detail was so limited that you couldn't say that it did or did not belong to anybody.' For the second appeal, the Metropolitan police had apparently trawled the country to find experts who agreed with theirs. They found some in Dorset and Strathclyde. On an initial examination, two experts in Glasgow each found 11 characteristics to identify the print as McNamee's. However, the two had not found the same eleven characteristics; and one of the Dorset experts said he wouldn't have used a number of the original Crown expert's identifying features. Cambridgeshire police, however, aligned themselves with Swann and insisted that there were insufficient identifying features (they could find only five) even to run a search of their computer system. Three other forces - Devon and Cornwall, Norfolk and Thames Valley - came to the Appeal Court specifically to put forward their view that the mark was not readable.

There is, as the judges made clear, a national fingerprint standard. The print found and the accused's fingerprint must have at least 16 matching characteristics. The jury at trial was told that this standard was reached; at appeal, however, not one of these 14 leading experts found more than 11 characteristics. The thumbprint evidence was, not surprisingly, dismissed, and McNamee's conviction was quashed. So, with professional standards seemingly in some disarray, are procedures to be tightened? Quite the reverse. From 3 April 2000, the current standard for fingerprint evidence will be abolished. It will no longer be necessary to show 16 characteristics, or indeed any particular number, to prove identification. This is because the Association of Chief Police Officers (ACPO) wants to make it easier to secure convictions. As far as can be ascertained, the vast majority of fingerprint experts are opposed to this change. In former years, it would have been straightforward to monitor the view of the profession at the annual National Conference of Fingerprint Experts. Unfortunately, this is no longer possible: ACPO has abolished the conference.

There are other cases in which the fingerprint evidence has been in dispute. In another Metropolitan Police case, concerning a burglary at the home of Miriam Stoppard, Andrew Chiory was charged. Fingerprints, having been triple-checked, were identified as his. He spent two months in prison, but was released when it was belatedly discovered that the prints were not his. The Criminal Cases Review Commission will now no doubt be examining all submissions which depend wholly or partly on disputed fingerprint evidence with even greater rigour. Also, at the same time as the McNamee appeal, a 25-year-old man in Huddersfield was convicted of murder on the basis of an ear-print. That case is already highly controversial. The examination of fingerprints depends on the expertise of those examining them. Since expertise varies, it seems essential to have an overall and objective standard. 'We all aim for the 16-point standard,' said Peter Swann. 'It has stood the test of time throughout the century. The vast majority of prints are clear. A problem arises only in a very few cases.'