MICHAEL HANRATTY (James Hanratty's brother): This thing has gone on for 40 years. It's, they've covered it up and this is the final cover-up.
NARRATOR (CATHY TYSON): Last week the Appeal Court upheld the conviction of James Hanratty. Tonight Horizon tells the extraordinary story of how breakthroughs in DNA science have transformed a bitter case of conflicting evidence, murder and justice.
VALERIE STORIE: I wish to state positively and categorically that there was no miscarriage of justice. There never was any such miscarriage of justice.
NARRATOR: 40 years ago a small-time thief called James Hanratty with no history of violent crime was hanged for a motiveless and horrific murder, but vital evidence, withheld from the original trial, suggested Hanratty may have been executed wrongly.
MICHAEL SHERRARD QC (James Hanratty's trial barrister): I really couldn't bring myself to take in that those who had concealed the evidence in a capital case could have been as wicked as that.
NARRATOR: At the same time, new DNA discoveries by forensic scientists told a very different story.
ROGER MANN (Forensic Science Service): I would consider in my opinion that it's beyond reasonable doubt that the DNA that we've discovered on the crime stains was deposited by James Hanratty during the commission of the crime.
MICHAEL HANRATTY: Rubbish. You know, Jimmy didn't do this, so how can they find his DNA. There must be an answer somewhere.
NARRATOR: If the interpretation of the DNA was right then James Hanratty was guilty, but if other new evidence, kept secret from the original trial, was right then Hanratty might be innocent. This was the question facing the Appeal Court: could science now resolve the case of the A6 killer? Early one morning just over 40 years ago this overgrown country lane was the scene of a terrible discovery. It was late summer 1961 and John Kerr was 18 years old.
JOHN KERR (Trial witness): Well that August I took this job for two weeks doing a traffic census at a position called Dead Man's Hill, which is about eight miles south of Bedford on the A6. As I walked up the road I began slowly to see that there were two bodies, or collections of something, lying right at the end of this road about 80m up. As I got a bit closer still I realised that one of them was a woman lying on her back and beyond her another figure, also on the back, and from the fact that he was wearing trousers it was clearly a man and so I got closer to the woman and I could see that she was bloodstained, her skirt rising up above her knees, but it was such a bizarre, extraordinary scene that I actually said to her, "Are you alright?" because there was no sign of alarm, carnage or anything awful having happened. It was just these two bodies lying, apparently peacefully, in this brilliant sunny day. Of course she said to me, "No, I've been shot."
NARRATOR: A lay-by on the A6 trunk road had become the scene of a mysterious act of shocking violence.
JOHN KERR: (ARCHIVE) I asked her what her name was. She said it was Valerie Storie. She said "please tell my parents. They'll be so worried about me," so I said, "well what has happened?"
(PRESENT DAY) She said, "we picked up a man around 9.30 last night near Slough. He drive us here and he shot me and he shot him." And I said at that point, "Is he dead?" and she said, "I think so."
NARRATOR: Valerie Storie's boyfriend, Michael Gregsten, was dead, shot twice through the back of the head.
ANTHONY McKINLAY GREGSTEN: Well his face had been blown off. I believe that my mother had to go and identify him in situ at the site of the murder.
NARRATOR: Janet Gregsten was still married to Michael, despite his affair with Valerie Storie. They had two small children, Simon aged eight and Anthony nearly two.
ANTHONY McKINLAY GREGSTEN: I can remember him as being very warm with a, with a soft voice, but of course I was very small, but I suppose over the years I asked my mother very many questions about him, so I have built up a picture. What he was like? Well he was very young when he died.
NARRATOR: Valerie Storie, herself aged only 22, had also been shot through the chest and spine and left for dead on the road. Valerie Storie was rushed by ambulance to Bedford General Hospital where doctors fought to save her life. She's been hit by a total of five bullets from a 38 calibre revolver all fired into her at close range. One shot had severed her spinal column. Paralysed from the waist down, Valerie Storie would never walk again, but she was at least alive. Some hours later she was transferred to an intensive care ward where nurses gave her blood-stained clothes to a police exhibits officer to be labelled and kept as evidence. These clothes included a piece of her underwear which was marked as Exhibit 26 and sent for analysis. Hidden in the microscopic fibres was proof that Valerie Storie had been raped.
ROGER MANN: Exhibit 26, Valerie Storie's knickers, there was semen found on those at the time. It was possible in those days to obtain a blood group from a, a semen sample and a blood group was obtained from the semen on Valerie Storie's knickers. Now this was found to be Group O. Michael Gregsten was not a Group O, so this established that the semen didn't, in fact, come from him.
NARRATOR: This routine test ruled out Valerie Storie's boyfriend, Michael Gregsten, but in 1961 forensic science could go no further than blood typing and a Group O blood type still included 40% of the male population, so Exhibit 26 with its telltale trace of the killer was filed away and forgotten. Nevertheless, a case was brought against 25-year-old James Hanratty, who was executed six months after the murder, on the basis of other, non-forensic evidence. Hanratty went to his death protesting his innocence claiming he'd been set up by the police. After he was hanged his family and thousands of others became convinced he was the victim of a terrible miscarriage of justice.
PAUL FOOT (Hanratty campaigner): I have been involved in a lot of injustice cases. All the Irish cases - Birmingham 6, Guildford 4 and so on - I've been involved in investigating and commenting on a lot of these things and really everything that comes out in the Hanratty case just simply proves when went on in all of those cases. The same old story, that certainly, the certainty of having the suspects and bending the evidence to fit the suspects. This is exactly what's happened in this case.
MICHAEL HANRATTY: How can they find the man guilty of murder and hang him if it wasn't, if he didn't do it? I have, for 40 years ago, these things can't happen. The only way they can ever happen is if he's been framed and the old Bill have set him up. The whole thing it's like a play.
JAMES HANRATTY (James Hanratty's father): (INTERVIEW) He said, "Dad, there's only one thing I want you to do is to clear my name. Tomorrow morning I'll take this like a man. They've pinned this onto me. I want you, Mum, Michael, Richard and Peter never let anybody say a wrong word about me. I want you to clear my name. " And that was it. He turned on his heel and walked away.
(ADDRESSING PRESS) There was doubt at Bedford when they executed him. They know they've got the evidence. Lord...
NARRATOR: Hanratty's father died without ever finding the evidence to clear his son's name. Then came DNA.
IAN EVETT (Forensic Science Service): We can now produce DNA profiles from quantities and material we would have considered almost unimaginable 20 years ago.
NARRATOR: Breakthroughs in the science of DNA profiling have revolutionised forensic detective work. In 1995, at the request of the Hanratty family, scientists returned to the original evidence from the case, including Exhibit 26.
JOHN BARK (Forensic Science Service): A small piece of Exhibit 26 had been retained on the case file and this had been noted and with the development of new DNA techniques it was thought that it was the right time to test this to see if we could find whose DNA was present on this piece of fabric.
NARRATOR: Scientists knew that Exhibit 26 could hold a vital clue to the killer's identity if only they could resurrect DNA from the decayed 30-year-old evidence. The tiny piece of fabric was immersed in sterile solution, shaken and centrifuged. Chemicals were added to destroy any cellular debris, the DNA-rich fluid refined to produce a clear, colourless liquid containing pure DNA. Each drop of refined solution will usually contain hundreds of strands of DNA, but with evidence as old as this the question was if the minute amount of DNA extracted would be enough to create a profile.
JOHN BARK: The fabric was taken, DNA was extracted from it and the technology at the time was applied, but unfortunately no profile was obtained.
NARRATOR: The hope that DNA might solve the A6 mystery had failed. Modern forensic science seemed able to achieve no more than was possible in the 1960s. In the hours after the murder a police hunt began which would eventually lead to James Hanratty. Detectives from the Bedfordshire police searched the crime scene and surrounding countryside, but found nothing to link the killer with the crime. Michael Gregsten's car, driven away by the killer, was found abandoned in Essex, but even the car revealed no forensic clues.
MICHAEL SHERRARD: No hair, no blood, no fibres, nothing at all was found that linked Hanratty to that motor-car.
NARRATOR: In fact nothing was ever found to link Hanratty forensically to the murder. Instead his arrest was the result of a strange and complex sequence of discoveries. 24 hours after the car, Metropolitan Police found something else. In the South London bus garage - the murder weapon, a .38 Enfield revolver wrapped in a handkerchief and hidden along with five boxes of ammunition under the back seat of a 36A bus. Three weeks later two spent cartridge cases were found in a Maida Vale dosshouse, the Vienna Hotel, and these matched the murder weapon. Hanratty had stayed in the Vienna Hotel on the day before the murder. He was put in a police line-up and picked out by Valerie Storie. Two other eye witnesses said they had seen Hanratty driving the murder car shortly before it was abandoned and so on October 14th 1961 James Hanratty was formally charged with the murder of Michael Gregsten and put on trial for his life. In January 1962 the trial began at Bedford Assizes. Defending Hanratty was a young barrister, Michael Sherrard, whose first task was to question the credibility of Valerie Storie's identification. It wasn't easy.
MICHAEL SHERRARD: Valerie Storie was a rather pathetic figure. She was brought into court on a stretcher and gave her evidence from a wheelchair. Everybody felt sorry for her. What she said had happened to her had happened, Gregsten had been murdered in her presence, she had been raped.
NARRATOR: Paralysed for life by a crime of shocking violence Valerie Storie was a powerful witness, utterly unshakeable in her conviction that James Hanratty was indeed the killer. In court her testimony was backed up by the two other witnesses. James Trower and John Skillet swore on oath they had both seen Hanratty driving the murder car. The case now began to turn on the evidence of eye-witnesses.
MICHAEL SHERRARD: The witness may be perfectly honest, absolutely convinced that he or she has identified the right man or woman and you're not going to be able to cross-examine them to show that they're lying "cos they're not lying, they're telling the truth as they see it.
NARRATOR: Hanratty, without a convincing alibi for the night of the murder, performed badly in court. John Kerr, who had first walked into the crime scene, now came face-to-face with the man accused of the killing.
JOHN KERR: He came across as a cocky, arrogant person who may not have looked a total killer - no, I don't say that - but he certainly looked a nasty piece of work.
NARRATOR: The case against Hanratty, built around the testimony of eye-witnesses, made worse by Hanratty's poor alibi, but without a single piece of decisive forensic evidence, came down, in the end, to a single question: who did the jury want to believe?
JOHN KERR: Given that really the whole thing depended upon Valerie Storie's word against his I think sometimes that Hanratty's demeanour and appearance probably weighed a great deal with the jury in coming to their decision.
ARCHIVE FILM REPORTER: The jury went to their room at 22 minutes past 11. The Judge refused them a transcript of the proceedings, but he let them have a list of witnesses and all the 136 exhibits in the case. Outside the Shire Hall the silent waiting crowd had the satisfaction of seeing the jury's lunch taken into them at one o'clock - cold meat and salad, peaches and cream.
NARRATOR: Convinced Hanratty was innocent, his family grew more hopeful with every hour that passed before the jury returned, as his brother Michael remembers.
MICHAEL HANRATTY: The jury was out nearly 10 hours and the longer it went Sherrard was saying well listen, we've got this in the bag, they, they're not going to come back at guilty now.
NARRATOR: By late evening the waiting was over.
ARCHIVE FILM REPORTER: Nearly 10 hours after they'd first retired and after the court had refilled three times, the jury filed back into the box. The Clerk of the Court asked the Foreman for their verdict. "Guilty my Lord". Cries from the public gallery. Hanratty was asked if he had anything to say. After a false start and a long pause he said, "I am innocent my Lord and I shall appeal." The black cap was draped on the Judge's wig. "James Hanratty, the sentence of the court is that you suffer death in the manner authorised by law and may God have mercy on your soul."
MICHAEL HANRATTY: The shock, I mean it was just like hitting you with a sledge-hammer you know you just, you just can't, can't believe it, you know.
MICHAEL SHERRARD: It was my duty to go down to the cells to see him. I really didn't know what I was going to say. It was within minutes of the Judge having passed sentence, with all the ritual trappings of the black cap and so on and he was handcuffed between two warders. I approached him and before I could say anything he had pulled his hand forward, manacled hand forward and took my hand and said, "You're not to upset yourself, sir, we'll appeal." And I said, "Yes, we'll appeal."
NARRATOR: The appeal failed. At eight o'clock on the morning of April 4th 1962, just six weeks after being sentenced, James Hanratty was hanged at Bedford jail in one of the last state executions in Great Britain. By the end of the 60s capital punishment had been abolished, but the deep concerns surrounding the Hanratty case refused to go away. In 1997 DNA work began again on the Hanratty case. Scientists were prompted to start re-testing because a new piece of evidence, called Exhibit 35, had emerged from the police files. The murder weapon and ammunition found in the bus had been wrapped in a man's white handkerchief. Now scientists decided to renew their attempts at DNA profiling, testing the handkerchief and also the remaining fragments of Valerie Storie's underwear. They had failed two years earlier, but were now hopeful because of advances in a DNA copying technique called PCR.
DR JONATHAN WHITAKER (Forensic Science Service): PCR, or the polymerase chain reaction, is a process that we use in the laboratory to copy the bits of DNA that we're interested in lots of times to enable us to get enough DNA to generate a DNA profile.
NARRATOR: Sometimes called molecular photocopying the polymerase chain reaction is a remarkable technique used to magnify small quantities of DNA. It works by subjecting the target DNA to intense heat, splitting the double stranded DNA into two separate, single stranded segments. As the mixture is cooled an enzyme called a polymerase starts to lock on to each separated single stranded DNA creating an exact copy of the missing half to make a new complete double stranded segment of DNA. Each cycle of PCR doubles the target DNA. By repeating the process scientists can soon have billions of exact copies of the DNA they want to test. The minute quantities of DNA extracted from both exhibits was subjected to 34 separate cycles of PCR magnification and this time there were results.
JONATHAN WHITAKER: When we generated profiles from the handkerchief and the knickers the, the first observation we saw was that these DNA profiles matched each other and this is what we would expect to find if they'd originated from the same person.
NARRATOR: The same matching DNA profile appearing on both exhibits meant that for the first time evidence had been linked forensically - science suggesting that the person who had raped Valerie Storie had also handled the murder weapon.
ROGER MANN: The profiles in this case were very rare, something like one in several hundred millions, so the chances of them coming from two independent people I would say are quite small, beyond reasonable doubt that they came from the same person, I would say.
NARRATOR: But for the moment that was all. Although scientists now had an exact DNA profile for the killer they were no closer to knowing who that person might be. Then in 1999 something else.
NEWSREADER (PETER SISSONS): The case of James Hanratty, who was hanged 37 years ago, is to be referred back to the Court of Appeal. James Hanratty was executed for killing a man on the A6 in Bedfordshire in 1962. The Criminal Cases Review Commission says there's a real possibility that the Court of Appeal will not uphold the conviction.
MICHAEL HANRATTY: It's like winning the Lottery, you know you, you can't explain. I've got anger, I've got everything mixed up.
NARRATOR: Nearly 40 years after James Hanratty's execution a multi-million pound investigation by the Criminal Cases Review Commission, the CCRC, had uncovered enough serious flaws in the original police inquiry to justify reopening the case. This new evidence included discoveries revealed by a forensic technique developed since the trial, the ESDA Test.
DR DAVID BAXENDALE (Forensic Document Examiner): Well ESDA works in a very similar way to an ordinary office photocopier, the main difference being that whereas a copier makes an image of a document this detects an image of the impressions left by handwriting on an overlying sheet.
NARRATOR: Tiny plastic granules coated with ink dust are drawn by an electrical charge into the impressions made on a piece of paper by whatever was written on the previous page. The CCRC had asked document specialist David Baxendale to pay particular attention to two crucial police interviews with James Hanratty.
DAVID BAXENDALE: The first one went from page one to page 15 and the second one from the lower part of page 15 to page 20.
NARRATOR: These two interviews were conducted by the police officers running the murder hunt - Detective Superintendent Robert Acott and his deputy Kenneth Oxford, but Hanratty had always denied that the statements recorded what he'd actually said.
MICHAEL SHERRARD: Hanratty said there were things in it that he never said, there were admissions of a kind that he'd never made and there were things missing that he had said he said from the statements.
NARRATOR: The Esda Tests quickly identified discrepancies in the interview records, discrepancies which are easily explained by David Baxendale.
DAVID BAXENDALE: The simplest explanation is that the present page four, which is part of the record of the first interview, was in fact rewritten after the conclusion of the second interview.
NARRATOR: Whatever reasons police had for rewriting parts of Hanratty's first interview after the completion of the second are unclear, but for some the simple fact that the interview record has been altered is enough to cast doubt over the credibility of the police.
TAMSIN ALLEN (Bindman & Partners, Hanratty Family Solicitors): If the jury had known that the police were lying, or if the Court of Appeal had known that the police were lying when they said the interview had been taken down, recorded as it was given, then the credibility of the police evidence as a whole would have been undermined.
IAN RUSSELL (Det. Chief Supt., Metropolitan Police): There were some discrepancies in the way in which those interviews were recorded by virtue of the rewritten pages, but the fact of the matter is that they do not appear to have been changed in any substantial way and it's one of those parts of this investigation which has been very difficult to come to any positive conclusion one way or the other.
NARRATOR: However, for Michael Sherrard at the time of the trial and before the days of Esda evidence there was still a sense of unease surrounding Detective Superintendent Acott.
MICHAEL SHERRARD When you're eyeball to eyeball with a senior police officer who swears in a good loud voice that your client said this, that and the other and you were going to challenge him, there's something between you and the officer which gives you the feeling he's not coming clean.
NARRATOR: Concerns about Detective Superintendent Acott's influence on the trial grew stronger with the investigation's next set of discoveries.
TAMSIN ALLEN: What they found was shocking. They went through two or three thousand undisclosed statements, as well as files and files and files. We have a list of 12,000 documents, many of which are files and contain many more documents, and there may well be more to find. I mean almost every time one looks at this something else appears.
IAN RUSSELL: Certain items were not disclosed, statements, evidence were, were not disclosed 40 years ago which undoubtedly would have been disclosed today and may have put the defence in a better position that they were at the time.
NARRATOR: Detective Superintendent Acott had withheld from the court vital witness sightings of the murder car and other pieces of evidence, including Michael Gregsten's car log book where Gregsten had meticulously recorded his mileage driven prior to the night of the murder. With this information Acott calculated in his own notebook Gregsten's car had travelled over 200 miles before it was abandoned, a fact supported by other undisclosed sightings of the car in different parts of the country and all suggesting a longer journey for the car than Acott proposed to the court. Had the court known about Gregsten's log book and the conflicting sightings of the car it would have cast doubt on the two witnesses's claim to have seen Hanratty driving the car near the Ilford side street at seven in the morning.
MICHAEL HANRATTY: Mr Acott knew that that car wasn't in Ilford at seven o'clock in the morning. He knew that them two witnesses never saw that car, but he still used them.
NARRATOR: Acott needed these two witnesses to support Valerie Storie's identification of Hanratty for a good reason. Hanratty had not been his original suspect. The man Acott first arrested was a violent, rootless drifter called Peter Alphon, but when this first suspect was put in an identity parade Valerie Storie picked out a completely different and entirely innocent person.
VALERIE STORIE: I made a mistake. The man had nothing to do with the, with the case. It was just one of those things.
NARRATOR: Without a positive identification by Valerie Storie the case against Peter Alphon collapsed, but by now cartridge cases from the murder weapon had been found in the hotel where Alphon was a guest, so Acott went back to the hotel to see who else had been staying there, a sequence of events which alarmed campaigners.
TAMSIN ALLEN: It almost looks as though they're casting around for the next available person. Having found cartridge cases in the hotel they're rather stuck with the hotel. It doesn't fill you with confidence that this is a proper inquiry and a thorough investigation.
NARRATOR: This was the dosshouse where James Hanratty was also a guest. Acott now put him in an identity parade and this time Valerie Storie successfully picked out the police suspect. The CCRC's investigation made Hanratty's conviction look more unsafe than ever. A suspect because he was staying in the same hotel as the man police first arrested; identified as driving the murder car by witnesses whose sighting was questionable; picked out of a second police line-up after the failure of Valerie Storie's first flawed identification of an entirely innocent man; not linked at the time by a single piece of forensic evidence to the car, the murder weapon or the crime scene. For his family Hanratty was hanged for being in the wrong place at the wrong time. A small time thief destroyed in court by detectives Acott and Oxford.
MICHAEL HANRATTY: My father always thought that, that the evidence was manufactured and he always said that Acott murdered his son and I feel that more so now. Acott and Oxford murdered my brother.
MICHAEL SHERRARD: The public were cheated, the system was cheated. I don't regard myself as having been cheated. I, I'm really an intermediate player, but Hanratty was hanged. He was cheated. If the other material that was not disclosed to us would have made the difference, so it, it's fair to say that there seems to be a strong argument at least for saying that the trial was fatally flawed and the word fatal has a real significance in this context.
NARRATOR: But over the years Valerie Storie's belief in her identification has not wavered.
VALERIE STORIE: Well I am convinced that Hanratty was guilty. He was tried by the law of the land, the jury found him guilty, he was sentenced. I, I don't think that we can all be wrong. Hanratty is guilty. There's just no question of doubt at all. These people who think they knew better, I mean they weren't on Dead Man's Hill that night in August. They, they weren't there, they don't really know anything about it.
NARRATOR: By the late 1990s the mystery surrounding the A6 murder seemed only to have deepened. At the same time the forensic work continued. Having obtained a matching DNA profile from the exhibits, scientists now began the task of identifying who this individual might be.
JONATHAN WHITAKER: In the absence of a, of a profile from James Hanratty to compare to the unknown profile we'd obtained from the handkerchief and the underwear, we then went to surviving Hanratty family members to see if there was any degree of relativeness with the unknown profile and their DNA profiles.
NARRATOR: Keen to rule out James Hanratty, his brother Michael and mother Mary volunteered samples of their own DNA allowing scientists to compare the profile of the unknown male with Hanratty family DNA. The results surprised everyone.
MICHAEL HANRATTY: They've made a mistake. It can't possibly be.
JONATHAN WHITAKER: We calculated that it was 2.5 million times more likely of obtaining the DNA profile from the underwear and the handkerchief if it had originated from a son of and a brother of Mary and Michael, as compared to somebody unknown and unrelated to them.
NARRATOR: This DNA was damning evidence, but for campaigners so much other evidence seemed to point to a terrible miscarriage of justice, but their reaction to the DNA was sceptical.
PAUL FOOT: I'm a complete illiterate in relation to the science of DNA, physics and so on. I know nothing about it at all. My doubts stem solely from my, a very, very clear belief that this man did not commit this murder, so if the science is saying he did commit the murder I say well that clashes with my belief that he didn't commit the murder and there must be something wrong with the science.
NARRATOR: In the lead up to the appeal, where all the new evidence would be reviewed, it seemed as though a stalemate had been reached. Then the Crown Prosecution Service took a step which shocked Hanratty's family. In October 2000 the court agreed to an application to dig up Hanratty's body so that forensic scientists could obtain a DNA profile from Hanratty himself.
PAUL FOOT: I thought the exhumation of the body was a slightly revolting and unpleasant and disgusting episode really. Typical public relations practice by the police and by the, the scientists who of course are desperately anxious to prove that they're right on this matter.
NARRATOR: Forensic scientists argued they could only assess the crime scene DNA if they could actually compare it with James Hanratty's DNA.
JOHN BARK: Exhumation did take place. We were able to obtain DNA from the remains and when we compare that DNA point by point with the DNA that we'd found on the handkerchief and on the knickers we found no discrepancies. We had a match there and therefore this considerably strengthened the evidence that we were looking at DNA from James Hanratty rather than anybody else in the population.
NARRATOR: The DNA found on the exhibits was hundreds of millions of times more likely to have come from James Hanratty than a random member of the public and, after 40 years of fighting the evidence, Hanratty campaigners weren't surprised when this confidential DNA data was leaked to the press in advance of the appeal, but for some DNA offered hope that the doubts surrounding the 40 year old crime might soon be over.
ANTHONY McKINLAY GREGSTEN: If you were to ask a perfect stranger who, who was murdered in the A6 murder they think for a minute and they say "Hanratty'.
NARRATOR: For Anthony Gregsten the real victims of the crime have been forgotten.
ANTHONY McKINLAY GREGSTEN: In the public eye Hanratty is now per, perceived as being guilty, so I feel I can lay my father's ghost to rest, in a manner of speaking.
NARRATOR: But for Hanratty campaigners the DNA clashes with everything they believe to be true.
GEOFFREY BINDMAN (Bindman & Partners, Hanratty Family Solicitors): You have had over 40 years steadily the case against James Hanratty disappearing, the case on the, on the evidence of witnesses, on the evidence of what actually happened and DNA comes along and says he was guilty.
NARRATOR: But what else, apart from Hanratty's guilt, could explain the DNA?
ROGER MANN: One possibility is that the DNA would have been deposited by the person who committed the crime. Another possibility would be that they were due to contamination. That means the DNA was deposited on the two items by some other means other than when the crime was, was committed.
NARRATOR: So those who believed James Hanratty to be innocent now had to explain how else, apart from at the murder itself, his DNA profile can have got onto the crime scene evidence and as they began to look into the science of DNA it did seem as though there were serious grounds to question the results. What scientists call contamination is a genuine and alarming outcome of PCR.
DR MARTIN EVISON (Forensic Anthropologist, University of Sheffield): Because we can detect DNA from as little as a single cell we only need a tiny amount of material for contamination to occur.
NARRATOR: PCR works incredibly efficiently but indiscriminately. Any DNA will be magnified into large, measurable quantities, even DNA that has got into the process accidentally.
DR MARTIN EVISON: All that's required is for somehow for some cells or some saliva or some sweat or something of that kind to get onto an exhibit.
ROGER MANN: You can't do forensic science in a vacuum. Contamination, by whatever means, is something we just have to accept as a, as a risk.
NARRATOR: Once it was known that something as small as a flake of Hanratty's skin could have contaminated the exhibits to produce DNA readings, it was clear when this contamination might have occurred. During the trial itself clothing from Hanratty and Valerie Storie was transported to and from court in the same cardboard boxes.
MICHAEL HANRATTY: They were all put in the same box. Jimmy's stuff, Valerie Storie's stuff, all into the same box. Taken away, brought back the next day. The investigating officer had to display it all on a table. He had the underwear, he had the handkerchief. There was nothing about DNA then. He had no gloves, no mask, anything. Now to me the guidelines of all this evidence, which they reckon proves Jimmy's without any doubt, has been done. To me I don't feel it is proper evidence because it hasn't been kept under the guidelines of what DNA is today.
DR MARTIN EVISON: I think there are a number of specific circumstances where I don't believe the possibility of contamination can be excluded. I think there is a possibility that contamination could have occurred.
TAMSIN ALLEN: To assume that, that DNA provides certainty and provides the truth is to give it too much weight. I think it's as subject to difficulties, to problems, to misunderstandings, to mistakes as any other sort of evidence.
NARRATOR: But the forensic scientists are absolutely confident that their DNA results are unaffected by contamination.
ROGER MANN: I think if you're trying to suggest that James Hanratty's DNA has got on to the crime stains as a result of contamination then I think that's unlikely.
NARRATOR: Their confidence stems from a simple act of logic. If James Hanratty is not the killer then where is the killer's DNA? For scientists can only find one male profile on the exhibits.
ROGER MANN: We only have one profile. That profile matches James Hanratty. If that was a contaminant, if that was due to contamination we would expect two profiles, one from James Hanratty due to the contamination and one from the original killer.
NARRATOR: So as both sides prepared for a final courtroom battle the stakes were high. The Hanratty family was still certain that evidence withheld from the original trial would have resulted in a totally different outcome. James Hanratty could have walked from court a free man. For campaigners DNA evidence alone has little to offer.
PAUL FOOT: There has to be some corroborative evidence before people are convicted solely on the scientific evidence, otherwise I think in this case we're liable to go on making a mistake. I mean we've made that mistake and it's had terrible repercussions, you know that is Jimmy Hanratty's dead, he's been hanged by the state and he's been hanged by the state on, on, in a case which was absolutely hopeless in my view.
NARRATOR: But the DNA undoubtedly is James Hanratty's and the theory this DNA was deposited there by contamination does not explain why only a single male profile, Hanratty's, has been found on the crime scene exhibits. For the police this is conclusive.
IAN RUSSELL: I think the DNA testing has provided very powerful evidence that the original conviction of James Hanratty was safe.
NARRATOR: The DNA is the single, decisive piece of forensic evidence missing from the original trial. Last week the Appeal Court judged that this DNA, standing alone, was certain proof of James Hanratty's guilt, evidence so powerful that it overwhelmed the years of doubt and uncertainty. The Appeal Court ruled that the jury at Bedford had come to the right answer and that Detectives Acott and Oxford had caught the right man, that what Valerie Storie said was unquestionably true and that the vicious murderer of Michael Gregsten was indeed James Hanratty, his guilt now confirmed by the microscopic traces of his DNA which had lived on 40 years after his execution.