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Latest in DNA analysis gains wider acceptance
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Cybergenetics' Mark W. Perlin, left, and Belfast Detective Chief Inspector Justyn Galloway talk about advanced DNA technology Friday at the Allegheny County Courthouse.
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When Mark W. Perlin landed Nov. 15 at Belfast International Airport, Northern Irish police escorted him to his hotel room, guarded his room around the clock then ushered him to Antrim Crown Court just outside of Belfast.
The Pittsburgh scientist had come as an expert DNA analyst in the murder trial of Brian Shivers and Colin Duffy, two members of the Real Irish Republican Army accused of the 2009 ambush murders of two British soldiers.
For three days in the witness box, he faced sometimes hostile cross-examination from defense lawyers concerning the reliability of his technology that definitively linked Mr. Shivers to the murders of two soldiers outside the Massereene Barracks' front gate.
The TrueAllele technology that Pittsburgh's Dr. Perlin developed also showed that the DNA of Mr. Shivers' co-defendant, Mr. Duffy, had been inside the getaway car at some point, but the judge would rule that Mr. Duffy's DNA could not link him directly to the crime.
The case put TrueAllele on the world stage, and Mr. Shivers' conviction drew international attention, including proclamations that it represents the future for forensic DNA analysis. Its key advantages include more detailed DNA match scores and the ability to analyze minuscule samples or mixtures of DNA from more than one person.
Dr. Perlin and Belfast Detective Chief Inspector Justyn Galloway discussed TrueAllele's role in providing key evidence in the Northern Ireland murders in a packed-house presentation Friday in the Allegheny County Courthouse.
The Perlin technology received additional support this week when the Pennsylvania Superior Court affirmed the first-degree murder conviction of former state Trooper Kevin Foley, who was convicted in 2009 of killing Blairsville dentist John Yelenic. It was Dr. Perlin's test that prosecutors relied on to show the jury that Mr. Foley's DNA was found under Dr. Yelenic's fingernails in a mixture of blood. The probability of the DNA match being a mere coincidence, Dr. Perlin testified, was 1 chance in 189 billion.
Dan Fitzsimmons, chief trial deputy district attorney for Allegheny County, said the opinion serves as a state legal precedent that will make it easier for prosecutors to use Dr. Perlin's test, now that the court has accepted it as valid science.
"The bottom line is his computer-based test to analyze [samples] can yield significantly better results," Mr. Fitzsimmons said, noting that many crime scene samples contain mixtures of DNA.
The TrueAllele DNA analysis that Dr. Perlin developed at his company, Cybergenetics in Oakland, offers a million-fold improvement in match statistics over human analysis, according to studies and actual case results. New York, Virginia and the Allegheny County Crime Lab have certified its use in cases and have begun using it.
But the Antrim case posed a real challenge for Dr. Perlin and put him in danger.
In court, the spectacle of "solicitors," "barristers" and Mr. Justice Anthony Hart in powdered wigs was offset by the lack of a jury or citizen witnesses. Threats of retaliation against those who testify or juries that rule against "dissident Republicans," have forced such cases to be tried solely on hard evidence and police and expert-witness testimony. The Northern Irish even use the euphemism "dissident Republican" rather than "terrorist" to describe IRA members to prevent reprisals.
On March 7, 2009, Patrick Azimkar, 21, of London, and Mark Quinsey, 23, of Birmingham were receiving a pizza delivery at the front gate of the Massereene barracks when two hooded assailants, captured on the barrack's security cameras, ambushed them and unleashed 65 rounds from Romanian AKM assault rifles. Six others including pizza delivery drivers and other soldiers were wounded severely but survived. The getaway car, driven by a third assailant, was found partially burned more than 7 miles from the barracks.
From that car, investigators obtained small amounts of "touch DNA" from a seat-belt buckle, a cell phone, and a burnt matchstick on the road beside the getaway car, but could not get a match statistic. So Dr. Perlin was summoned to analyze several DNA samples.
TrueAllele calculates a match score for two or more sets of DNA by determining how much more probable is a match than mere coincidence. A match score that reduces the probability of coincidence to one in a million is considered persuasive evidence. But match statistics of a billion or a trillion to one provide a definitive match between crime-scene and a suspect's DNA.
In Antrim, Dr. Perlin testified that the match his technology produced between DNA from the burnt matchstick that ignited the car and Mr. Shivers' DNA was 1.1 million times greater than chance, with his match to DNA on the cell phone to be 6 billion times more probable than chance. His testimony helped convince Justice Hart to find Mr. Shivers, 46, guilty of the murders and sentence him to 25 years in prison -- essentially a life sentence considering Mr. Shivers has advanced-stage cystic fibrosis.
TrueAllele calculated a link between Mr. Duffy's DNA and DNA from a seat-belt buckle to be 6 trillion times more probable than chance and almost as strong a link to an unused matchstick inside the car. But Justice Hart acquitted Mr. Duffy of all charges. The DNA match placed him inside the car but could not prove his involvement in the murders.
Dr. Perlin's technology has been used successfully in other murder trials, including the conviction of a Reading, Berks County, man for the murder of his former lover, and to help to identify victims of the 9/11 terrorist attack in New York City.
Detective Galloway said DNA evidence provided by TrueAllele had never been used in United Kingdom or Irish courts, which was the reason why defense lawyers tried to exclude it from trial.
Ruling that Dr. Perlin's testimony was admissible, Justice Hart said he observed Dr. Perlin as he gave evidence and considered the claims made about his credibility and reliability as an expert. "I am satisfied that his evidence in this trial has not been shown to have gone beyond the boundaries of the high standards of truthfulness and objectivity demanded of witnesses in this jurisdiction."
His ruling sets a precedent for TrueAllele's use "in other UK investigations where DNA evidence is central to the investigation," Detective Galloway said.
In the Massereene case, Dr. Perlin said, "science itself was on trial, but TrueAllele withstood the challenge and has joined the forensic arsenal in the fight against crime."
First Published February 18, 2012 12:00 am
