The Historic Enquiries Team, which was asked to review all the violent deaths of the Troubles, has now assembled a database "the size of a B&Q", according to the head of the unit, writes Liam Clarke.
The data is held in the "most advanced central store in the UK", according to Dave Cox, climate-controlled and its access managed by computer. The information on the 3,268 killings is linked by a specially designed analytical database that groups the deaths – paramilitary murders and security force killings – into 2,516 separate incidents.
The material for this giant repository was gathered from police stations across the province, as well as military records, MI5 case papers and published sources. Its location is being kept secret for fear of sabotage. Some particularly sensitive files relating to security force collusion are held in London under the care of a "white team" of retired detectives.
"It has everything we can think of," said Cox. "Ballistic linking, description of suspects, vehicles, modus operandi. We can pull out details of all the red-headed gunmen, or whatever, and can draw inferences. Gap analysis has been one of the most useful tools, looking at what stopped when someone was killed or imprisoned. That can give you a good bet on who was responsible for a death."
Cox was often the first police officer to visit bereaved relatives after Troubles murders up to 30 years ago. The experience can still reduce the former Metropolitan police detective to tears.
The database has become a useful resource for the families of victims who are unsure about the precise circumstances in which their relatives died. "It was unbelievable to have someone come; it was such a comfort and they were so professional. I couldn't find words to praise them enough," said Eugene Reavey, a South Armagh builder whose three brothers were murdered by loyalists in January 1976.
The murders may have been carried out with the help of rogue security force members linked to a group known as the Glenanne gang. It is suspected of planning or carrying out more than 125 murders, including the Dublin and Monaghan bombings of 1974 which left 33 people dead.
The day after the Reavey murders the South Armagh Republican Action Force – thought to be a cover for IRA members on ceasefire at the time – murdered 10 Protestant workers on a factory minibus. Reavey, who was driving with family members and friends to to collect his brothers' bodies, was one of the first on the scene and rumours circulated that he had been involved in the attack.
Last year Ian Paisley made the accusation in the House of Commons under parliamentary privilege, quoting what appears to have been a UDR document. Police now suspect it may have been tampered with in order to blacken Reavey's name before it was given to Paisley.
The dead men were also accused of other previous attacks. Reavey promised his father on his deathbed that he would clear the family's name. Because of the smears against them, Reavey and his mother were frequently harassed by the security forces and he was forced to pay more than £1.3m in protection money to loyalist paramilitaries.
Last January, Cox finally dispelled the smear on behalf of the PSNI and the British government. "He walked into my mother's house and said he was there on behalf of the prime minister and the chief constable to apologise for the death of her sons," Reavey said. "He said that after reading all the evidence he could confirm that her sons were the victims of a senseless sectarian murder campaign."
Cox handed over a letter apologising for the "appalling harassment suffered by the family in the aftermath at the hands of the security forces".