Séamus Turlough McElwaine, a volunteer in the South Fermanagh Brigade of the Provisional Irish Republican Army (PIRA), is killed on April 26, 1986, by the Special Air Service (SAS) while on active duty with Seán Lynch, who is seriously injured in the shooting.

McElwaine is born on April 1, 1960, the oldest of eight children, in the townland of Knockacullion, beside the hamlet and townland of Knockatallon, near the village of Scotstown in the north of County Monaghan. At the age of 14, he takes his first steps towards becoming involved in physical force republicanism when he joins Na Fianna Éireann. Two years later he turns down an opportunity to study in the United States and joins the Irish Republican Army (IRA), stating “no one will ever be able to accuse me of running away.”

McElwaine becomes Officer Commanding of the IRA in County Fermanagh by the age of 19. On February 5, 1980, he kills off-duty Ulster Defence Regiment (UDR) corporal Aubrey Abercrombie as he drives a tractor in the townland of Drumacabranagher, near Florencecourt. Later that year, on September 23, he kills off-duty Royal Ulster Constabulary (RUC) Reserve Constable Ernest Johnston outside his home in Rosslea. He is suspected of involvement in at least ten other killings.

On March 14, 1981, a detachment of the British Army surrounds a farmhouse near Rosslea, containing McElwaine and three other IRA members. Despite being armed with four rifles, including an Armalite, the IRA members surrender and are arrested. While on remand in Crumlin Road Gaol, McElwaine stands in the February 1982 Irish general election as an independent candidate for Cavan–Monaghan and receives 3,974 votes (6.84% of the vote). In May 1982 he is convicted of murdering the RUC and UDR members, with the judge describing him as a “dangerous killer” and recommending he spend at least 30 years in prison.

On September 25, 1983, McElwaine is involved in the Maze Prison escape, the largest break-out of prisoners in Europe since World War II and in British prison history. Thirty-eight republican prisoners, armed with six handguns, hijack a prison meals lorry and smash their way out of the prison. After the escape McElwaine joins an IRA Active Service Unit operating in the area of the border between Counties Monaghan and Fermanagh. The unit targets police and military patrols with gun and bomb attacks, while sleeping rough in barns and outhouses to avoid capture.

McElwaine holds a meeting with Pádraig McKearney and Jim Lynagh, members of the Provisional IRA East Tyrone Brigade, in which they discuss forming a flying column aimed at destroying police stations to create IRA-controlled zones within Northern Ireland. However, this plan never materialises. McKearney and Lynagh are later themselves killed in the Loughgall ambush.

On April 26, 1986, McElwaine and another IRA member, Seán Lynch, are preparing to ambush a British Army patrol near Rosslea, County Fermanagh when they are ambushed themselves by a detachment from the Special Air Service Regiment. Both are wounded but Lynch manages to crawl away. A January 1993 inquest jury returns a verdict that McElwaine had been unlawfully killed. The jury rules the soldiers had opened fire without giving him a chance to surrender, and that he was shot dead five minutes after being wounded. The Director of Public Prosecutions requests a full report on the inquest from the RUC, but no one has been prosecuted for McElwaine’s death.

McElwaine is buried in Scotstown, with his funeral attended by an estimated 3,000 people, including Gerry Adams and Martin McGuinness. McGuinness gives an oration describing McElwaine as “a brave intelligent soldier, a young man who gave up his youth to fight for the freedom of his country” and “an Irish freedom fighter murdered by British terrorists.”

In 1987 McElwaine’s father, Jimmy, a longtime member of Monaghan County Council, became the chairman of the Séamus McElwain Cumann of Republican Sinn Féin.

On April 1, 1990, a monument to McElwaine is erected in Corlat, County Monaghan. The oration is given by a Catholic priest, Father Piaras Ó Dúill, who compares McElwaine to Nelson Mandela, saying they both had the same attitude to oppression, and both refused to denounce principle. The inscription on the monument is a quote from Patrick Pearse: “As long as Ireland is unfree the only honourable attitude for Irishmen and Irishwomen is an attitude of revolt.” A monument to McElwaine and six other republicans is erected in Rosslea in 1998 and unveiled by veteran republican Joe Cahill.