The former head of the Irish Republic's forensic state laboratory has said he is surprised no-one was ever prosecuted for the IRA killing of 18 British soldiers.
Dr James O'Donovan told an inquiry in Dublin evidence against two suspects arrested by gardai on the day of the Narrow Water bombing had been quite good.
The attack, on August 27 1979, caused the highest death toll suffered by the British Army in a single incident during the Troubles, and came just hours after the Queen's cousin Lord Louis Mountbatten was killed when a bomb exploded on his boat off County Sligo. The majority of the dead were paratroopers.
Dr James Donovan, the founder and former director of the Irish state laboratory, told the Smithwick Tribunal he was surprised prime suspects Brendan Burns and Joe Brennan were never prosecuted.
"Why was the Criminal Prosecution Act not used?" he asked under-cross examination. I thought the evidence was good on the basis that they gave false name and addresses, they were arrested on a motorcycle that had been near the scene of the detonation."
The retired forensic scientist continued: "There were cigarette butts, saliva samples, one of them had fern material in his underpants. Go to the law library and you would not find many with fern in their underpants," he added. "On summation the evidence was quite good."
The two suspects were arrested on the day of the blast, but later released.
The tribunal previously heard claims from an unnamed senior RUC officer that police in the Irish Republic were ordered by a former Taoiseach not to co-operate with the investigation into the bombing because of paratroopers' involvement in the Bloody Sunday shootings in Londonderry.
Mr Burns was killed in 1988 when a bomb he was transporting exploded prematurely, while Mr Brennan was later convicted of firearms charges in Northern Ireland.
The Smithwick Tribunal is investigating allegations of Garda collusion in the IRA killing of two senior RUC officers, Chief Superintendent Harry Breen and Superintendent Bob Buchanan, in Dundalk in 1989, minutes after they left a meeting with gardai.