A pioneering method of genetic analysis could have major implications in future UK trials after helping to deliver a conviction in the Massereene Baracks murder case..
The high-profile case in Antrim saw a pioneering method of analysing genetic samples recovered from a crime scene accepted in a British courtroom for the very first time, opening the way for its use in future trials.
The computer-based statistical technique has emerged as an alternative to the long-established human review process in the last decade.
The True Allele casework system, developed by American scientist Dr Mark Perlin, has been used to examine samples containing mixed DNA traces when traditional lab analysis failed to identify a clear genetic profile of an individual.
After interpreting the sample, Dr Perlin's computer programme derives a likelihood ratio on whether the profile obtained matches a suspect or victim.
He carried out tests on DNA data from a seatbelt buckle, a mobile phone and a single matchstick found in or around the Vauxhall Cavalier, which was abandoned partially burnt-out on a country road just a few miles from the shootings.
The academic said that genetic material found on the buckle was 5.91 trillion times more likely to be Duffy's than someone else's, while a sample from inside the phone was 6.01 billion times more likely to belong to Shivers than another person.
The expert also concluded that the DNA on the matchstick was 1.1 million times more likely to be Shivers than someone else's.
In one of the quirks of the non-jury trial system, all those findings were presented in court before judge Justice Antony Hart decided whether they would actually be admitted as evidence.
Dr Perlin flew from his base in Pittsburgh, Pennsylvania to deliver the results in person and faced three days of intensive scrutiny in the witness box.
The defendants' lawyers insisted his method was not yet accepted by the scientific community and its reliability had not been sufficiently proved.
They pointed out that it had never been admitted in a UK or Irish court and had only been used in handful of cases in the US.
The court also heard of one case where a judge in England decided not to accept Dr Perlin's evidence. But the academic robustly defended his technique.
He said his system had been subjected to rigorous validation tests by the US's National Institute of Standards and Technology, was now accepted by the FBI and had recently been approved for use in the New York police's forensic labs.
Dr Perlin told the court his method was used in the aftermath of the World Trade Centre attacks on 9/11 to help identify victims' charred remains.
After hearing legal submissions from defence and prosecution lawyers on the merits of True Allele, Judge Hart took three days to deliberate on whether the evidence should be accepted.
Ultimately he decided the technique was reliable.
"I am satisfied that the stage has now been reached in the case of this system where it can be regarded as being reliable and acceptable and I am satisfied that Dr Perlin has given his evidence in a credible and reliable fashion," he said.
"In the light of this conclusion I can see no basis under which I could possibly exercise my discretion to exclude this evidence and I therefore admit it in evidence."
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