The John Tonge Centre, DNA evidence and miscarriages of justice - Part 4

When the February 2005 Belzer report, which criticised flawed DNA testing procedures and recommended an independent audit of Queensland’s John Tonge Centre, was leaked to the Queensland media, it was compounded by another forensic biologist, Kris Bentley. She also trenchantly criticised the management process, inaccurate DNA results and invalidated testing equipment used at the John Tonge Centre when she resigned on March 4, 2005.

Attempts to avert an ongoing scandal and maintain damage control forced the embattled Queensland Minister for Health, Gordon Nuttall, to order an independent review of the quality and management control of crucial DNA testing at Queensland’s John Tonge Centre.

On March 3, 2005 Mr Nuttall told the Queensland media, “I believe the review is in the best interests of the justice system and the people of Queensland”.

Mr Nuttall told the waiting media that an overseas scientific expert from New Zealand's Environmental Science and Research facility (ESR) would review the John Tonge Centre to “clear the air” and would make recommendations “that will enhance the valuable work being currently undertaken” at the Centre. What Mr Nuttall did not tell the media was that the New Zealand ESR had already experienced the same problems as the  Centre but with catastrophic results.

ESR's Mt Albert laboratories found themselves at the centre of two high profile cases which serve as textbook examples of what can go wrong in DNA testing laboratories - even those which are fully accredited and meet internationally accepted quality control guidelines.

The Peter Howse case

In 1996 a serial sex offender, Peter Robert Howse, was arrested for the rape of a teenager on the basis of strong evidence which included identification by a witness. Samples taken from Howse and the victim were sent to ESR labs for testing but ESR reported no match and eliminated Howse as a suspect. He was released from custody.

In 1999 Howse was arrested and tested again in connection with at least three further rapes. In the meantime ESR had switched to STR (PCR) testing. The results strongly implicated Howse in the 1996 rape as well as those being investigated. An inquiry ordered by the New Zealand Department of Justice found that ESR had failed to gain a result with the 1996 tests, but laboratory policy had led to “no result” being reported as “no match”.

ESR conceded that “with hindsight” it might have been better if failure to get a result was reported as such, but explained that they adopted a “conservative” approach to reporting in order to give the accused the benefit of any doubt.

The case of "Profile N"

Another forensic blunder at ESR occurred when blood samples from an assault victim in Christchurch were sent to ESR for testing. The result of this test came to be dubbed “Profile N” by the inquiries which were to follow. At the time the Christchurch blood samples were being tested at the ESR facility, Wellington police were investigating two murders.

Operation “Pad” had collected evidence from the crime scene of Bill Fleet’s murder in his home. There were witnesses to the killing and a man had been arrested and charged. Blood stains on a roller door at the murder scene were sampled and sent to ESR for analysis. Operation “Rex” concerned an earlier murder on gang-premises at Porirua. Some weeks later Mr Kuka Tiai was arrested and charged. He immediately confessed, saying he had acted alone. Samples from the crime scene and the deceased were also sent to ESR.

Samples from under the fingernails of the deceased and from spots on a wardrobe at the scene produced a profile which failed to match either Mr Tiai or his victim. Suspecting an accomplice police requested that ESR conduct a search of its database for matching profiles. ESR found two. One was from the roller-door sample taken in Operation “Pad” and the other was “Profile N”, which ESR claimed was likely to occur in only one New Zealander in 930 million.

The Christchurch assault victim was subjected to “extensive police inquiries” for more than three months and his financial records were seized. They established that he had not left Christchurch around the time of the murders. In fact he hardly left Christchurch at all.

During the Sharman Inquiry, which investigated the forensic blunder, ESR suggested that the assault victim may have had a brother who had been at the crime scenes and this factor would have greatly increased the chances of gaining a matching profile. When it was revealed that the Christchurch man had no brothers ESR countered with the possibility of an unknown half-brother. The Sharman Inquiry seemed to accept that this was a possibility but the later Eichelbaum-Scott inquiry was less charitable.

Sir Thomas Eichelbaum and Professor John Scott, assisted by an impressive array of legal, forensic and scientific experts, conducted a thorough investigation into the collection, transport, storage, testing and analysis of the samples in question, reporting in November 1999.

Although they never discovered exactly how the mistakes had happened they did determine that the “Rex” and “Pad” samples had been accidentally contaminated with DNA from “Profile N” at an early stage of processing at ESR's Mt Albert laboratories. Extracts from them sent to other laboratories for testing also returned “Profile N”. Numerous recommendations for improving oversight, record keeping and even laboratory ventilation were made.

During the inquiry ESR was asked to check the results of all testing done in July 1998 for any further instances of “Profile N”. Although they initially reported that none were found, later re-tests showed a partial profile consistent with “N” in another sample from “Pad”. They also revealed 25 other “unexplained” profiles in 14 of the 36 samples tested that month.

The David Dougherty case

The independence, neutrality and objectivity of the DNA testing at ESR was seriously challenged when an 11-year-old girl was abducted from her West Auckland home and raped in October 1992. The traumatised young victim described her attacker as clean-shaven but identified her moustached neighbour, David Dougherty, as the offender. Dougherty submitted a DNA sample so that he might be eliminated as a suspect.

The RFLP DNA tests performed at New Zealand's ESR laboratories were unable to gain a result from the semen stains on the girl's underwear and pyjamas. In June 1993 David Dougherty was convicted of abduction and rape and sentenced to seven years and nine months in prison.

In 1993 ESR also introduced DQ-alpha profiling which can return results from very small quantities of DNA but with a limited degree of resolution. Dougherty's defence team requested that the evidence in his case be re-tested using the new technique. The tests were paid for by David Dougherty’s father.

DQ-alpha testing was performed in October 1993 by Dr Peta Stringer of ESR. Stringer identified the DNA of another man in the semen stains but in an act of either professional incompetence or personal malevolence she claimed that faint readings below the threshold of detection recommended by the test kit manufacturers meant that Dougherty could not be excluded as a possible offender even though the DNA did not belong to him or the complainant.

Dougherty’s October 1994 appeal was dismissed as a result of Stringer’s interpretation of the DNA found in the semen stains but it was a molecular biologist, Arie Geursen, who recognised Stringer’s evidence was seriously flawed and consulted with Murray Gibson who had taken over Dougherty’s defence.

Geursen sent samples of the evidence to forensic scientists in Australia and the US who agreed that the faint readings which Stringer said implicated Dougherty were nothing more than artefacts of the testing process. Peta Stringer was now the only expert saying that DNA testing did not eliminate Dougherty as the rapist.

While Dougherty consistently maintained his innocence he served over three years imprisonment in some of New Zealand’s toughest jails before his conviction became the target of Auckland Sunday Star-Times journalist, Donna Chisholm, who questioned the DNA testing procedures at ESR. Chisholm’s investigations revealed the bias of Stringer’s evidence when notes of a 1994 telephone conversation with the Crown Prosecutor indicated that Stringer had an interest in the outcome of the case after she asked “if it will all be enough to get him off?” referring to the unidentified DNA.

Together with forensic scientist Arie Geursen and New Zealand lawyer Murray Gibson, Donna Chisholm began a relentless pursuit for the truth that resulted in a campaign by Auckland Sunday-Star Times to free Dougherty.

Gibson successfully petitioned the New Zealand Governor-General in June 1996 and Dougherty was granted an appeal against his conviction. Two months later the New Zealand Court of Criminal Appeal quashed Dougherty's conviction and ordered a re-trial stating that the interpretation of the ESR results by three independent scientists was materially different from Stringer’s interpretation. Dougherty was finally released from prison after three years and nine months pending re-trial.

In April 1997 a New Zealand High Court jury acquitted Dougherty on all charges but he was yet to clear his name in the eyes of the public. In November 1997 New Zealand Justice Minister, Doug Graham, told the New Zealand media that Dougherty had not proved his innocence “on the balance of probabilities”.

Three years later, following a further series of tests with the most sophisticated equipment available - all of which failed to detect the slightest trace of his DNA in the stains, Dougherty was finally found to have proved his innocence and was compensated almost NZ$900,000 for wrongful imprisonment.

Chisholm and the Auckland Sunday Star-Times were vindicated in their pursuit of justice for an innocent man and the newspaper editorialised:

The David Dougherty case raises serious questions about New Zealand's justice system. An innocent man spent more than three years in jail. He was finally released, not by the efforts of those who run the system, but as the result of a campaign by a scientist, a lawyer and a journalist. The campaign revealed serious errors of judgment by a state forensic scientist. It also exposed a worrying official culture which appears to favour the prosecution rather than the defence.

In response to an allegation by New Zealand prosecutor Mark Woolford that Donna Chisholm and the Sunday Star-Times were guilty of irresponsible reporting the newspaper responded:

Prosecutor Mark Woolford has accused the Sunday Star-Times of irresponsible reporting. Journalist Donna Chisholm, he claims, has acted as a campaigner, not as a journalist. Woolford is hopelessly muddled. This newspaper reported the flaws in the prosecution case and the prosecution, naturally enough, did not like it. It revealed the shortcomings in Stringer's evidence and the misguided attitudes of the ESR and neither Stringer nor the ESR liked that either. Exposing injustice and campaigning for the truth are not irresponsible acts, Mr Woolford: they are the greatest glories of the free press. We are immensely proud of our role in the campaign for justice for David Dougherty.

Finally, in September 2002, another arrest was made over the attack that had caused David Dougherty’s wrongful imprisonment. He is now universally recognised as an innocent man while the forensic scientist whose unprofessional conduct condemned him to over three years of imprisonment and a decade of public vilification migrated to Australia.

Dr Peta Stringer was employed at the Victorian Forensic Science Centre where she is credited with developing the “CrimTrac” DNA database policy whereby a “hit” is declared if 16 or more pairs of the 18 genetic markers in two samples match, although it takes 18 out of 18 markers to make a true match and any less is either a lab error or an exclusion. When a match policy like that advocated by Stringer is used on a large DNA database it could generate an exaggerated rate of “cold hits” that carries a significant risk of wrongful convictions. But as Dr Stringer told a Victorian parliamentary inquiry into DNA databases: “There are a number of ways that you can count matches”.

The independence of DNA testing facilities and the integrity of the personnel using them must be of the highest standard if DNA evidence is to continue being accepted as quality evidence in courts of law. That quality of evidence falls into disrepute when scientific objectivity and neutrality is replaced with a culture of forensic elitism that is significantly tailored to the prosecutorial pursuit of suspects through the judicial system.