McMahon had been held in Mountjoy jail in Dublin in recent years after dissociating himself from the Provisional IRA. He trained as a carpenter and had been on day release since early 1996, returning each evening to the prison.He had been one of the longest-serving prisoners in the Irish penal system and was one of those expected to be released in near future.
He was arrested close to the scene and just before the bombing that killed Lord Mountbatten and three others when a bomb exploded under a boat near the Mountbatten holiday home at Mullaghmore, Co Sligo. He was the only man convicted of the bombing, which also killed Lord Mountbatten's 14- year-old grandson, Timothy Knatchbull, Lady Brabourne, 82, and a local boy, Paul Maxwell, although police believed a six-strong gang was responsible.
Believed to have been the man who made the bomb after being trained in explosives in Libya, he tried unsuccessfully to escape on two occasions in the 1980s, both times using a smuggled firearm, before severing his links with the republicans.
His release follows the freeing from Portlaoise prison last Friday of six IRA prisoners under the agreement terms.
Earlier this week,Mo Mowlam, Secretary of State for Northern Ireland, looked forward to the freeing of terrorists held in Northern Ireland.
Ulster's prisoner release scheme got under way in earnest today as paramilitary prisoners in the Maze began filling in their application forms in the countdown to their release.The first group could be out as early as the end of this month. About 200 are set to get out in the first wave of releases.
Longer serving prisoners, like the Brighton bomber Patrick Magee, graveyard killer Michael Stone and loyalist leader Johnny "Mad Dog" Adair, are likely to be back on the streets within the first year of the scheme. Victims will be notified individually when Ulster prisoners who have offended against them are about to walk free. But they will have no say in the timing of releases.
The Ulster Unionist MP Jeffrey Donaldson condemned the decision to free McMahon.
He said: "Once again the release of this notorious killer is another indication of the premature manner in which both the Irish and British governments are approaching the release of terrorist prisoners.
"Even Sinn Fein admit the IRA war is not over, yet both governments continue with the release of prisoners in spite of on-going violence from republicans, including the IRA. Many will view this ... as yet another major concession to the IRA."
Victims of terrorist violence in Northern Ireland will come face-to face- with former prisoners under a new scheme aimed at healing divisions, it also emerged yesterday.
As the prisoner release scheme got under way, it was disclosed that both Protestant and Catholic relatives of victims have been asked to sit down with freed paramilitaries.
A group called Victims of Trauma is working with the republican pressure group Saoirse to bring the two sides together in the next fortnight.