It was claimed by Royal Ulster Constabulary ( RUC ) Special Patrol Group ( SPG ) officer John Weir , that the UVF killers were Robin Jackson ( who was also allegedly involved in the 1974 Dublin car bombings as well as a series of sectarian killings ) , Robert McConnell , and Harris Boyle . The men , including Weir , were all members of the Glenanne gang , which was made up of rogue elements of the RUC , Ulster Defence Regiment , regular British Army , and the UVF Mid-Ulster Brigade . These allegations were published in the 2003 Barron Report , which was the findings of an official investigation of the bombings by Irish Supreme Court Justice Henry Barron . In the same report , Weir claimed that he had received information from an informer that British Army captain Robert Nairac was also involved in Green 's killing . The 1993 Yorkshire Television documentary '' The Hidden Hand : The Forgotten Massacre '' states that Robin Jackson and his UVF comrades were controlled by Nairac , who was attached to 14th Intelligence Company . Secret Intelligence Service operative Captain Fred Holroyd also asserted that Nairac had executed Green , who was , according to Holroyd , commander of the Provisional Battalion of North Armagh . Captain Holroyd claimed that Nairac boasted about the killing and had shown him a colour polaroid photograph of Green 's corpse taken after the killing . Holroyd also told the Garda Síochána that he had received a photograph of Green some months prior to his killing . Holroyd enlarged the photograph and had it distributed . He believed from that time until Green 's death , 4 Field Survey Troop , one of the three sub-units of the 14th Intelligence Company led by Captains Nairac and Tony Ball , had Green placed under surveillance . Nairac 's claim has been discounted by two Garda investigations which revealed that the polaroid was one of a series taken of Green 's body by a Garda officer the morning following his fatal shooting
1974 Dublin car bombings
Dublin and Monaghan bombings
John Francis Green