The McMahon Murders occurred on 24 March 1922 in Belfast when six Irish Catholic civilians were shot dead and two wounded by policemen of the Ulster Special Constabulary (USC) or Royal Irish Constabulary (RIC). The dead were aged between 15 and 50 and all but one were members of the McMahon family. The policemen broke into their house at night and shot all eight males inside. It is believed to have been a reprisal for the IRA's killing of two policemen the day before.

Northern Ireland had been created 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 Protestant and unionist - were implicated in a number of attacks on Catholic and Irish nationalist civilians as reprisal for IRA attacks.


The killings occurred after the acceptance of the Anglo-Irish Treaty, but with the violence of the Irish War of Independence still raging in the new political entity of Northern Ireland. The Treaty copper-fastened the Partition of Ireland, which was first established in the Government of Ireland Act (1920). 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 Unionist authorities established the Ulster Special Constabulary (USC). This was an armed, almost exclusively Protestant reserve police force, which was first deployed in February 1921. The USC had a generally hostile relationship with the Catholic, Irish nationalist community in Belfast and elsewhere. Lynch writes of the USC: "some were polite and courteous, others merely arrogant and destructive whilst a small anonymous minority set out to kill".

The MacMahon killings are believed to have been a reprisal for IRA's killing of two USC policemen in Belfast. At lunch time on 23 March 1922, USC constables Thomas Cunningham and William Cairnside were patrolling Great Victoria Street in the city centre when they were approached by a group of IRA members and shot dead. Two Catholics, Peter Murphy (61) and Sarah McShane (15), were shot dead in a suspected reprisal attack several hours later in the Catholic Short Strand area by unidentified gunmen.

Neither Owen McMahon nor his family had any involvement in the shooting of the policemen, nor were they involved with either Sinn Féin or the IRA. McMahon was in fact a supporter and personal friend of Joseph Devlin, the Irish Parliamentary Party Member of Parliament, who rejected Irish republican violence. McMahon was a prosperous businessman, who owned several pubs in Belfast and had at one time been chairman of the Northern Vintners' Association. His home at Kinnaird Terrace, off the Antrim Road in north-central Belfast, was described as a 'sprawling Victorian mansion'.

The killings:

At around 1:00 am, two uniformed policemen seized a sledgehammer from a city council workman, who was guarding a building site at Carlisle Circus. At nearby Clifton Avenue they met three other policemen and the party of five proceeded to the home of Owen McMahon. They used the sledgehammer to break into the house, where eight males and three women were present. Once inside, they herded the males into the living room and the women into a drawing room. The men were told, "you boys say your prayers", before the police opened fire. The shooting would continue for five minutes; five of the men were killed outright and two were wounded, one fatally.

Owen McMahon (Father) (50), Gerard McMahon (15), Frank McMahon (24), Patrick McMahon (22) and Edward McKinney (25) were killed outright while Bernard McMahon (26) died later. The youngest McMahon son, 12-year-old Michael, survived the attack by hiding behind furniture and pretending to be hit. Another son, John (30), survived despite serious gunshot wounds.

Eliza McMahon, Owen's wife, raised the alarm by opening the drawing room window and shouting "Murder! Murder!" A matron at an adjoining nursing home was alerted and phoned the police and an ambulance.

The killers were identified by John MacMahon as police, "Four of the five men were dressed in the uniform of the RIC but, from their appearance, I know they are Specials, not regular RIC". It has been alleged that Detective Inspector John Nixon and a group of policemen operating out of Brown Square barracks in the Shankill Road area were behind the killings, but this has not been proven. An inquiry was carried out by the Defense Ministry of the Irish Free State, but not by the Northern Ireland authorities. Twelve policemen, including Nixon, were named in the Free State's 1924 report as having carried out the murders, as well as several other attacks on Catholics.


The attacks caused outrage among Belfast's Catholic population and over 10,000 people attended the funerals of those killed. At the funeral Mass for the victims at St Patrick's Church, Reverend Bernard Laverty told the congregation that even the Black and Tans "had not been guilty of anything approaching this crime in its unspeakable barbarity". The McMahons had been "done to death merely because they were Catholics", but he told the mourners to practise "patience and forbearance" and not to seek revenge.

Irish Nationalist Party MP Joe Devlin told the British Parliament, "If Catholics have no revolvers to protect themselves they are murdered. If they have revolvers they are flogged and sentenced to death".

David Lloyd George and Winston Churchill, concerned that the violence would cause the collapse of the new Northern Ireland administration, organised a meeting in London between southern nationalist leader Michael Collins and James Craig, premier of Northern Ireland, both to try to stop IRA attacks (tacitly supported by Collins) and to pressure Craig to provide more protection for Catholics. Craig denied the nationalist assertion that the McMahon killings were part of an anti-Catholic pogrom on behalf of state forces, telling the Northern Ireland parliament that, "no such thing has ever been the policy of Protestants here...The Ulster men are up against, not Catholics but ... up against rebels, that they are up against murder, Bolshevism and up against those enemies not only of Ulster but of the (British) Empire".

No one was prosecuted for the killings but DI Nixon was expelled from the Royal Ulster Constabulary, albeit on full pension, in 1924 for giving (in breach of police regulations) a political speech to an Orange Order meeting saying that, "not an inch of Ulster should be yielded" to the Free State.

The attacks were part of a series of reprisals on Catholics in general for IRA attacks in Belfast and elsewhere. The following week saw an incident known as the "Arnon Street Massacre", in which five Catholics were killed by uniformed police in revenge for the killing of a policeman on the Old Lodge Road. In total, 452 people would be killed in Belfast in the conflict between June 1920 and July 1922 - 267 Catholics and 185 Protestants.