Sniper unit equipped with deadliest rifle ever made
In the early 1980s, after 18 paratroopers were killed in an IRA landmine attack at Warrenpoint, the British army and RUC withdrew ground transport from south Armagh and began building a line of observation posts from Newry to the Monaghan salient. All troops and police transport was by air, and the new posts were massively fortified against car-bomb and mortar attack.
This effectively removed all military and police targets from one of the strongest areas of IRA support. From the mid-1980s to early 1990s there were few British military casualties.
In response, the IRA began searching for ways to breach the army's defences and came up with the idea of long-range sniping attacks. The troops still had to come out of their bases to carry out ground patrolling and in support of police checkpoints.
In 1985 the IRA leadership sent arms buyers to the United States to acquire the most powerful sniper rifle ever built, the Barrett Firearms M82A1 12.7 mm semiautomatic rifle.
The rifle was used by US troops in the Gulf War against radar, aircraft and even armoured command vehicles.
It has an absolute range of about five miles and an accurate sniping range of over a mile. Its effect on human targets is devastating, and no body armour provides protection against it.
One of the rifles was intercepted by gardai at Dublin Airport in November 1985 on a cargo plane from New York. Another was intercepted at the Central Sorting Office in Dublin in August 1986 when it arrived in the post from Chicago, broken into component parts.
The first Barrett, along with other sniper rifles, is believed to have reached south Armagh early in 1992.
The sniper unit claimed its first victim on August 25th that year when Private Paul Turner, who was only 18, was killed by a high-velocity shot that passed through his body armour and killed him instantly as he stood at a checkpoint on the outskirts of Crossmaglen.
Two RUC constables and five soldiers were killed in 1993, three in the vicinity of Crossmaglen.
The last member of the security forces to be killed by the sniper unit before the IRA ceasefire was Grenadier Daniel Blinco (22), who was shot on December 30th just after the IRA's Christmas ceasefire ended.
When the IRA ended its ceasefire in February 1996 the unit resumed its operations, killing Lance Bombardier Stephen Restorick a year later.
The unit was commanded by Michael McGinn (41), a long-serving Provisional IRA member from Castleblayney. The principal sniper is believed to have been Michael Caraher (31), from Cullyhanna, whose brother, Feargal, was shot dead by British soldiers at a checkpoint in south Armagh in 1990.
The arrests by undercover police and soldiers, probably backed by members of the British domestic security service, MI5, meant they could successfully penetrate the IRA's last major stronghold.
Despite the heavy sentences handed down on the four yesterday all will benefit from the early-release programme and be freed by July next year.