McMahon killings

The McMahon killings or the McMahon murders occurred on 24 March 1922 in Belfast, Northern Ireland, when six Catholic civilians were shot dead, of whom five were McMahon family members, a father and four of his sons. Two others were wounded and a female family member was assaulted. The dead were aged between 15 and 50, and all but one were members of the McMahon family. The gunmen broke into their house at night and shot all eight males inside. It is believed to have been a reprisal for the Irish Republican Army's (IRA) murder of two policemen the previous day.

Northern Ireland had been created within Ulster ten months beforehand, in the midst of the Irish War of Independence. During this time, its police forces – especially the USC, which was almost exclusively Ulster Protestant and unionist – were implicated in a number of attacks on Catholic and Irish nationalist civilians as reprisal for IRA actions.

The killings occurred after the acceptance of the Anglo-Irish Treaty, but with violence still ongoing in the new state of Northern Ireland. The Treaty copper-fastened the Partition of Ireland, which was first established in the Government of Ireland Act. In the first half of 1922 however, in the words of historian Robert Lynch, the Irish Republican Army (IRA), "would make one final attempt to undermine the ever hardening reality of partition by launching an all out offensive on the recently established province of Northern Ireland".

To counter this, the new unionist Government of Northern Ireland established the Ulster Special Constabulary (USC), a reserve police force to the Royal Irish Constabulary, which was first deployed in February 1921. The USC had a mutually hostile relationship with both pro-Treaty nationalists and anti-Treaty republicans in the area which became Northern Ireland, especially in Belfast. Lynch writes of the USC: "some were polite and courteous, others merely arrogant and destructive whilst a small anonymous minority set out to kill".