DNA Tests Unreliable and Unproven
ON the 12th day of the Trial, the defence team made their final submissions to the Judge as he prepares to make a ruling on the admissibility of DNA evidence from the prosecution's main expert witness.
Controversial forensic evidence against Colin and Brian should be rejected because the testing method is unreliable and unproven, barristers for the two men have argued.
Defence barristers suggested Dr Perlin had a conflict of interest because he wanted his method to gain commercial credibility so he could sell it for more than $100,000 per customer. They also claimed he was using the data generated by his system selectively and accused him of lacking transparency about his methods because of commercial confidentiality.
Both defence barristers spent the day summarising their objections to the evidence most of which focused on the ability of Dr Mark Perlin to be a 'reliable expert witness' and the validity of his True Allele forensic method.
Dr Perlin's "True Allele" method of analysing mixed genetic samples and deriving a likelihood ratio is relatively new and has never once been admitted as evidence in a UK or Irish court, and only on a few occasions in the United States.
The method of testing DNA is unreliable and selective, defence lawyers have said.
Defence submissions
Opening his submission, Barry MacDonald, who represents Colin told the court that his objections were based on three key points. He said:
"Firstly, there is a material and significant conflict of interests which means he is not reliable as an independent witness.
Secondly, the method used has not been proven to be significantly reliable enough to be accepted.
“Lastly, the admission of his evidence would have an adverse impact on the fairness of the trial and on that basis, the court should not admit it."
Mr McDonald told the court:: "The validation of new scientific methods and processes should only be regarded as having been achieved if they are accepted by the wider scientific community. That has not happened in the present case."
Patrick O'Connor, who represents Brian, told Antrim Crown Court: "He is partisan and lacks all impartiality in relation to the merits and the limits of his system and that is a violation of his duty. "He has demonstrated disdain and contempt for even the most eminent of those who do not follow his methods and that is why we suggest he is a man on a mission who has lost his objectivity."
Mr O'Connor added: "This is a man who will (turn down) no opportunity to support what he sees as a major contribution to the world of science and he is on a mission to promote it."
The National Institute for Science and Technology in the US is assessing his methods.
Mr O'Connor added: "This is quite remarkable really, that the court should be invited to take a leap in the dark when the one authoritative body in the jurisdiction from which this technology has emanated is currently engaged in an assessment process."
Mr O'Connor also told the court that he felt the method used by Dr Perlin was 'not sufficiently reliable'.
In a summary of his objections, he said: "He has failed to fulfil his duty of candour to the court and he has negligently misled the court in his evidence. “It is my submission that he lacks the necessary impartiality to be an expert witness in this trail."
FBI
Both solicitors further pressed issues which have arisen from the previous cross-examination of Dr Perlin including the suggestion by the defence that he stood to 'gain financially' from a ruling in his favour and his 'failure to disclose' all the results from his tests.
Mr McDonald pointed out that Dr Perlin had admitted that only a 'small fraction' of forensic labs use his method and the majority still favour a threshold method which discounts data which is not deemed to be of a high enough quality.
He added: "There has been no form of accreditation of this method in this jurisdiction and in the only case in England, the evidence was not allowed."
Mr O'Connor said it was 'quite remarkable' that the court had been invited to 'take a leap in the dark' on a method which was currently going through the process of being validated by a body in America.
He also pointed out that under their own guidelines, the FBI did not use this forensic method but still opted for the 'conventional' method.
Referring to the method in which Dr Perlin came to his conclusions and claiming it was 'impossible' for an outsider to validate them, Mr O'Connor called it a 'violation of due process' and added that 'Dr Perlin had a selective approach to the data which was examined'.
Mr Justice Hart told the court on Monday that he planned to deliver his ruling on the admissibility of DNA evidence by Dr Perlin on Wednesday morning.