THE guns used to slaughter 10 Protestant workmen at Kingsmills on January 5, 1976 were used in 110 other murders and attempted murders, a report is expected to find.
A report into the massacre by the Historical Enquiries Team (HET), which the relatives of the victims will receive on Thursday, is also expected to confirm for the first time the IRA were responsible.
The IRA have never admitted involvement and were meant to have been on ceasefire at the time. A group called the South Armagh Republican Action Force claimed the killings.
It is understood the weapons used in the murders were used in 110 other attacks, including the murder of five Orangemen at Tullyvallen, the killing of RUC officers, chief supt Harry Breen and supt Bob Buchanan, as well as the murder of victims campaigner Willie Frazer’s father.
Mr Frazer, speaking for the families, said they plan to ask for the Red Cross and Amnesty International’s backing to have the murders probed as war crimes.
The ten workmen, aged between 19 and 58, had been in a minibus driving home from work at a textile factory in Glenanne when the vehicle was stopped. An IRA gang asked one man identified as a Catholic to “get out of the way” before machine gunning the rest of the 11 men.
Ten died. Only Alan Black survived despite being shot 18 times.
It is understood the massacre at Kingsmills was months in the planning.
On January 5, 1976, a Ford Transit minibus was carrying a mixed workforce of 16 home from work in Glenanne to Bessbrook. Five were Catholics and 11 were Protestants. Four of the Catholics got out at Whitecross, while the remainder continued on the road to Bessbrook.
As the bus cleared the rise of a hill, it was stopped by a man standing on the road and flashing a torch. As it stopped, 11 masked gunmen emerged from the hedges.
The workers assumed that they were being stopped and searched by an Army or RUC checkpoint, and when ordered to line up beside the bus, they obeyed.
At this point the lead gunman ordered the only Catholic, Richard Hughes, to step forward. Hughes’ workmates thinking that the armed men were loyalists who had come to kill him – tried to stop him from identifying himself. However, when Hughes stepped forward he was told to “get down the road and don’t look back”.
The remaining 11 men were shot with more than 100 rounds in less than a minute. Ten of them were killed outright while Mr Black survived despite having 18 gunshot wounds.
Nine of the dead were from the village of Bessbrook, while the bus driver was from nearby Mountnorris.
The attack was attributed as the reason that the government decided to bring the SAS into south Armagh.
The HET report into the murders was due to have been released in January but was held back until this week.
Mr Frazer said the families plan to call for an inquiry into the murders because he has claimed the police investigation into the incident was “non existent”.
Representatives of the families have said they wish to thank the victims’ group FAIR for their persistence in seeking to get to the truth.