The Arnon Street Killings, also referred to as the Arnon Street murders or Arnon Street massacre, took place on 1 April 1922 in Belfast. Six Catholic civilians were killed by Ulster Special Constabulary (USC) or Royal Irish Constabulary (RIC) police officers in retaliation for the killing of an RIC officer by the Irish Republican Army (IRA).
Although the Irish War of Independence was "officially" ended in July 1921, the IRA's conflict with British and Northern Ireland forces continued and indeed escalated in the first half of 1922. The IRA, with the tacit assistance of Michael Collins (head of the new Irish Free State) continued to wage a guerrilla war in Northern Ireland. According to historian Alan Parkinson, despite "the IRA having some short term successes...the main effect of this intensive campaign was to unleash a terrible backlash on the Catholic population in Belfast". Only a week before the Arnon Street incident, elements of the police - either Royal Irish Constabulary (RIC) or Ulster Special Constabulary (USC) - had killed six Catholic civilians in the McMahon murders.
On the evening of 1 April an RIC constable, George Turner, was patrolling the Old Lodge Road, when he was killed by a sniper's bullet. Almost immediately, his colleagues sought revenge on local Catholics.
About ten police officers in Brown Square Barracks, upon hearing of the killing, took a Lancia armoured car and went touring the republican/nationalist streets in the area. When they dismounted their vehicle, witnesses heard them shouting "Cut the guts out of them for the murder of Turner". Their first victim was John McRory (40) who lived on Stanhope Street, just across the road from where Constable Turner had been shot. The police broke into his house and shot him dead in his kitchen. In Park Street, father of seven Bernard McKenna (42) was killed while lying in bed. Finally, the police arrived at Arnon Street.
William Spallen (70) lived at 16 Arnon street and had just returned from the funeral of his wife (who had also been killed in the conflict). His 12-year-old grandson Gerald Tumelty witnessed his death: "Two men came into the room, one was in the uniform of a policeman. They asked my grandfather his name and he said William Spallen. The man in plain clothes fired three shots at him. When I cried out he said "lie down or I will put a bullet into you". Tumelty said the killers then took £20 that his grandfather had to pay for his wife's funeral.
The attackers then used a sledgehammer to break into the house next door, where they found Joseph Walsh (39) in bed with his seven-year-old son Michael and his two-year-old daughter Briget. Joseph Walsh was bludgeoned to death with the sledgehammer while Michael Walsh was shot and died from his wounds the next day. Another son, Frank (14), was shot in the thigh but survived. A local man, George Murray, described the aftermath of the attack: "One of the three policemen had revolvers and the other two had guns. These men went out. Immediately after, seven armed men - five in police uniform and two in civilians clothes - entered".
Later that evening, another Catholic, John Mallon (60) was shot dead in Skegoneill Avenue, though possibly not by the same gunmen.
The unionist press, the Belfast Newsletter and Belfast Telegraph, condemned the killings but did not identify the killers as police. The Dublin-based Irish Independent wrote that "never even in the worst state of terror in the west and south has the state of affairs which now prevails in the Northern capital been experienced". Michael Collins wrote an angry telegram to Northern Ireland Prime Minister James Craig, demanding a joint inquiry into the killings. No such inquiry was set up.
As with the McMahon murders of the week before, it was strongly suspected that an RIC Detective Inspector, Nixon, operating out of the Brown Street Police barracks, had organised the attack. Nixon and several other policemen failed to turn up at roll call at the barracks immediately after the killings. According to Tim Pat Coogan, "in the atmosphere of the time neither Craig nor the British could or would prosecute or investigate such men without risk of a serious backlash amongst the Specials (Special Constabulary)".
According to Alan Parkinson, "the raw sectarianism of many violent acts during this period were not confined to large scale incidents such as the Arnon Street or the McMahon murders, nor indeed to any one political or religious group". For instance, the day before the Arnon street killings, IRA members threw a grenade though the window of the house of Protestant Francis Donnelly, killing his two-year-old son Frank and mortally wounding another son, Joseph (12).
According to historian Robert Lynch's count, a total of 465 people died in Belfast in the conflict of 1920 - 22, and a further 1,091 were wounded. Of the dead, 159 were Protestant civilians, 258 Catholic civilians, 35 British forces and 12 IRA volunteers.