A DNA expert told the court that DNA evidence used as part of the prosecution case against Colin and Brian cannot establish all the circumstances in the case against them.

The small size of the sample used in relation to both men is also cause for serious concern, according to Ohio professor Dan Krane

Prof Dan Krane said the DNA in the case against Colin was in small amounts and did not necessarily mean he had been in direct contact with the getaway car.  It could have got there through secondary transfer.

Prof Krane said: "What it establishes is that his DNA may be associated with the glove and it may be associated with the belt buckle of the car.

"The presence of a DNA profile per se does not say anything about the timeframe or the circumstances under which the DNA came to be there.

"The DNA tests themselves cannot answer that type of question.

"That is left more to a court or a jury to decide what those circumstances and timeframe (are). The DNA tests can simply tell us that DNA was found on those items."

Prof Krane told the court that the sample relating to Colin came from a mixture of DNA from two or more people, meaning there was a possibility that somebody other than Mr Duffy came into contact with the glove.

He said Dr Mark Perlin, a prosecution witness who used his own "True Allele" DNA analysis method to link the accused to the getaway car, did not have a proper understanding of certain effects associated with the research.

Prosecution barrister Terence Mooney QC said the witness had opposed efforts to advance the use of DNA analysis.

"As soon as you lose the battle on an issue you move to another one and create more confusion," he said.

"Throughout your career in giving evidence in forensic cases you have tried to build up impediments to the advance of DNA being used in court."

Prof Krane disagreed.

Brian gives evidence

Brian told the court he had nothing whatsoever to do with the attack at Massereene.

He said he had been to about three or four meetings of the republican political group Eirigi at the invitation of his friend Dominic McGinchey but had never joined the group, nor had he been inspired by it and he had no desire to be involved in anything political.

Brian also said he had never even met Colin prior to his arrest.

He also told the court he suffered from cystic fibrosis from an early age and in the November before the attacks on Massereene barracks, he had gone to the hospital with his fiancée to be told he had only five or six years left to live.

He said that was hard hitting and said he had other things in life to do rather than getting involved in anything like that.

Under cross-examination by the prosecution he said he would often smoke cigarettes with Dominic McGlinchey, who had been arrested and released after the Masserene shootings.

Brian said it had become a running joke that Mr McGlinchey would often disappear with his matches.

Brian outlined his movements on the day of the attack.  He claimed that he had been invited to attend a farewell party for some foreign friends at a pub, and also insisted that he was not a member of any paramilitary organisation, and was opposed to violence.

The prosecution barrister put it to him there were too many coincidences at play.

Prosecution barrister Terence Mooney QC put to him: "You were involved in this attack along with your friend Dominic McGlinchey."

He added: "I suggest you have indicated your support by the attendance at meetings at an organisation that can only be described as at the dissident side of republicanism.

"You have manipulated your fiancee to try and concoct a story."

Brian denied the accusations.