Story highlights Brian Shivers had been convicted before but the judgment was quashed

Judge finds DNA evidence in a getaway car is not convincing

Two English soldiers were gunned down outside barracks in Northern Ireland in 2009

A 47-year-old man from Northern Ireland was found not guilty Friday of murder in the 2009 killings of two British soldiers at an army base in Northern Ireland.

Brian Shivers had been accused of killing Patrick Azimkar, 21, and Mark Quinsey, 23, two English soldiers gunned down outside Massereene Barracks.

The off-duty and unarmed servicemen were ambushed with gunfire as they collected a pizza delivery at the front gate of the base, hours before they were due to leave for a tour of Afghanistan. They were the first members of the British security forces to be killed in Northern Ireland since the signing of the Good Friday peace agreement in 1998.

The Real IRA, a splinter group of the Irish Republican Army, claimed responsibility for the attack.

Shivers had been convicted of the murders last year and ordered to serve at least 25 years in jail. The Northern Ireland Court of Appeal quashed that judgment this year after Shivers challenged the trial verdict. He was then ordered to face a retrial.

Prosecutors said Shivers' DNA was found on matchsticks and a mobile phone found in and around an abandoned getaway car.

The defense said the DNA did not prove he was involved in the shooting and could have been innocently associated with people who used the car.

Shivers' attorney has described him as an "unlikely terrorist" because he had cystic fibrosis and a doctor had told him he only had a few years to live.

The judge effectively sided with the defense, saying the evidence wasn't strong enough.

Another man, Colin Duffy, had been acquitted last year.

Shivers also was acquitted of attempting to kill four other soldiers and two pizza delivery men and torching a getaway car.