A 27-year-old Toombridge man has been jailed for life for the murder of his ex-partner's sister and attempting to murder the mother of his two children in a double shooting incident in Bellaghy last year.
A jury was sworn in at Londonderry Crown Court on Wednesday for Phelim McNally's trial.
But in a dramatic turn of events on Thursday, he changed his plea and admitted murdering 18-year-old Lauren O'Neill and attempting to murder her 22-year-old sister Brenda.
The shootings took place in Brenda's south Derry home in William Court, Bellaghy on May 19 last year.
In an almost inaudible whisper McNally, from Station Road in Toome, pleaded guilty before a packed Belfast Crown Court, where his case had been listed at the last minute as a 'mention'.
Following his pleas, Mr Justice Treacy told McNally the only sentence the court could pass was one of life imprisonment, but that later this month he would "deal with the question of the appropriate tariff", setting out how long he must serve of the life term.
On Wednesday when the jury was sworn, they had been told that at the time of the double shooting Brenda O'Neill was McNally's former partner and Lauren was her younger sister. They also heard that the three principal witnesses in the case would be Brenda herself and her parents, Laurence and Bernadette.
By his guilty plea, McNally has at least saved them that ordeal, as well as members of his own family who were also expected to give evidence together with paramedics, police and forensic officers, and civilians.
An earlier court hearing heard that at the time of the horrific shooting McNally's two young children then aged three years, and ten months, were present in the house before he opened fire.
The court also heard that young Lauren, who had just turned 18, was killed making the ultimate scarifice - trying to protect her big sister who managed, despite being seriously wounded herself, to make it to a neighbour's home to raise the alarm.
Brenda O'Neill, who had to undergo emergency surgery, was to spend over three weeks in hospital and so missed Lauren's funeral, which was attended by, Deputy First Minister Martin McGuinness, Mid Ulster Sinn Fein MLA Francie Brolly, SDLP Assembly Member Patsy McGlone and Magherafelt council chairman Ian Milne.
The devoted sisters were both past pupils of St Mary's College in Clady, near Portglenone, and had worked in McNally's Inn and Restaurant on the main Belfast to Derry Road, threes miles from Bellaghy.
Following the attack, Bellaghy parish priest Father Andrew Dolan, speaking on behalf of the heartbroken family, said: "Theirs is a mixed grief.
"They have one daughter coming home to them and they are so thankful for that, and that the children in the house weren't hurt, but they have another daughter who will never come home."
Brenda, surrounded by family and friends left Court 13 at Belfast's Laganside Courtroom on Thursday, not wanting to comment on proceedings nor on McNally's change of heart.
The murder was the second time tragedy had struck the McNally family.
On November 24, 1988, just hours before his wife Pauline gave birth to their sixth child, McNally's father, also named Phelim, was shot dead by UVF terrorists. At the time it was suspected his brother Francis, a Sinn Fein Councillor for Cookstown, was the intended target.
On the 20th anniversary of his murder in 2008, Deputy First Minister Martin McGuinness helped unveil a harp-shaped memorial to him.