John Oliver Weir (born 1950) is an Ulster loyalist born and raised in the Republic of Ireland. He served as an officer in Northern Ireland's Royal Ulster Constabulary's (RUC) Special Patrol Group (SPG) (a tactical reserve unit), and was a volunteer in the illegal Ulster Volunteer Force (UVF). As a member of the UVF's Mid-Ulster Brigade led by Robin "the Jackal" Jackson, Weir was a part of the Glenanne gang, a group of loyalist extremists that carried out sectarian attacks mainly in the County Armagh area in the mid-1970s.

Weir and his RUC colleague Billy McCaughey were convicted of the 1977 sectarian killing of Catholic chemist William Strathearn and sentenced to life imprisonment. Weir's affidavit which implicated Jackson, other members of the Glenanne gang, soldiers of the Ulster Defence Regiment (UDR), and his colleagues in the RUC and SPG, in a series of sectarian attacks, including the Dublin and Monaghan bombings, was published in the 2003 Barron Report, the findings of an official investigation into the 1974 car bombings commissioned by Irish Supreme Court Justice Henry Barron.

John Weir (loyalist)

Early life and the RUC

Weir was born in 1950 in County Monaghan in the Republic of Ireland to Church of Ireland parents on an estate near Castleblayney, where his father was employed as a gamekeeper. Raised in County Monaghan, he was later educated at The King's Hospital, a Protestant private school in Dublin. Over six feet tall, powerfully built, with blond hair and blue eyes, he had an imposing physical presence, which made him stand out in a crowd.

John Weir (loyalist)

Initially he had considered joining the Garda Síochána, the police force of the Republic of Ireland; however, in keeping with his family's political traditions, he opted to join Northern Ireland's police force, the Royal Ulster Constabulary (RUC), in March 1970 when he was 20 years of age.

John Weir (loyalist)

Upon his completion of training in Enniskillen Training Depot, he was first posted to the Strandtown RUC station in loyalist east Belfast. He was transferred to Armagh RUC station in 1972, and it was there on 1 August 1973 he was recruited into the Special Patrol Group (SPG), which was the RUC's "anti-terrorist" unit. It was made up entirely of Protestants. His duties involved making early morning arrests, evacuation of civilians at the scenes of suspect bombs and responding to explosions and shootings, as well as riot control. He claimed the SPG officers were "very anti-republican, and sectarian attitudes were common". Weir and his colleagues routinely beat up Catholics suspected of harbouring republican sentiments.

The SPG saw themselves as being the main police line of defence against all terrorist organisations but mainly the atrocities of the outlawed Provisional Irish Republican Army (IRA); who were responsible for more deaths than any other group and as such they considered the republican paramilitaries to be the main threat although they often came under attack from the Ulster loyalist paramilitaries. By the end of 1973, members of the SPG decided that due to the political " softly softly " stance of mainly but not exclusively Labour government policies they would have to "break the rules to curb the terrorists", by which they meant republican paramilitaries. Following the killing of an Ulster Defence Regiment (UDR) officer in 1974 by the IRA, rumours spread that Weir had been involved in the UVF's cross-border killing of prominent IRA man John Francis Green in County Monaghan. Just before Green's killing, Weir had discovered that Green had been using a safe house just over the border and tipped off his RUC Special Branch colleagues. He was therefore sent for his own safety to the SPG unit in Castlereagh, Belfast, on 25 January 1975, fifteen days after Green's shooting.

On 1 September 1976, he was transferred to Omagh where he spent six weeks at Lisanelly Camp. On 11 October 1976 he was promoted to the rank of sergeant and was again transferred, this time to Newry RUC station. He remained in Newry until November 1977, when he was sent to Newtownhamilton RUC station. His next posting was to Dunmurry, Belfast, in April 1978 and his final posting was in Magherafelt, County Londonderry, on 4 September 1978.