US father and daughter, Tom and Molly Martens, have dramatically won a challenge against their convictions for the murder of Irish businessman Jason Corbett (39) and now face the likelihood of a full retrial.
They were convicted almost three years ago of the second degree murder of Mr Corbett at his Panther Creek Court home in North Carolina on August 2 2015.
Their trial dominated headlines in both Ireland and the US.
Now, the North Carolina Court of Appeals has sensationally upheld their challenge to the convictions - to the shock and dismay of Mr Corbett's Limerick-based family.
The full judgement on the appeal will be posted by the US court later today.
Because the appeal was upheld by majority rather than unanimous verdict, it will go to the North Carolina Supreme Court for review.
It will be a matter for the North Carolina Supreme Court to order a retrial.
However, it is a normal course for retrials to be ordered in those circumstances.
North Carolina prosecutors are now pressing for a Supreme Court review having opposed the appeal.
The convictions will now be set aside and it is expected that a new trial in Davidson County will be ordered.
It is a major legal victory for the Martens after a Davidson County judge refused in 2018 to order a retrial after they alleged juror misconduct.
However, the North Carolina ruling has devastated Mr Corbett's Limerick-based family who fought a determined battle to see Tom and Molly Martens face justice over the packaging industry executive's brutal killing.
Members of the family had flown to Raleigh in January 2019 for the appeal hearing to support North Carolina prosecutors.
One family member said they were "shocked and heartbroken" by the Court of Appeal judgement.
Mr Corbett's sister, Tracey Corbett-Lynch, who had spearheaded a determined campaign for justice by the Irish family, said she was too upset to comment on the appeal decision.
"We are aware of the decision of the North Carolina Court of Appeal in relation to the retrial of the Martens," she said.
"We will not be commenting at this time on the decision and we would ask that our family's privacy would be respected.
"We will not be making any further comment at this time."
The decision by the three judge Court of Appeal panel followed an oral hearing in Raleigh, North Carolina last January.
Tom (68) and Molly (34) Martens battered the Irish businessman and father of two to death as he lay asleep and helpless in bed.
Their trial before a Davidson County Superior Court jury heard they then delayed alerting emergency services to the incident ensure Mr Corbett was dead when paramedics arrived.
Mr Corbett's two children were asleep in an upstairs bedroom when the fatal attack occurred.
Tom Martens, a retired FBI agent, claimed he acted in self-defence and alleged Mr Corbett had been attacking his second wife, Molly, who is Mr Martens daughter.
However, the Corbett family maintained that the Irish businessman was planning to bring his children back to his native Limerick amid
increasing concerns over his wife's mental health problems.
The trial heard that an attempt had been made to drug Mr Corbett - and that he was beaten so savagely by a metal baseball bat and heavy concrete brick that his skull fragmented.
One blow was inflicted after Mr Corbett was already dead.
Both Tom and Molly Martens were found to be uninjured at the scene.
Mr Corbett's first wife - the mother of his two children - died from a tragic asthma attack and he met Ms Martens when the Tennessee woman moved to Ireland to work as a nanny for his children.
They married in the US in 2011 but she visited a divorce lawyer just months later to determine her rights to his two children.
On conviction by unanimous jury verdict, the US father and daughter immediately launched appeals against their 20-25 year prison terms.
In January 2019, the North Carolina Court of Appeal heard arguments before a three judge panel from both the defence teams and the prosecution.
Since Mr Corbett's killing in August 2015, Mr Corbett's sister, Tracey Lynch, and her family has fought a determined battle to bring his killers to justice.
One US Special Attorney General argued, in defence of the appeal, that the only thing strange about the case was that the retired FBI agent and his daughter weren't charged with the first degree murder of the Limerick father of two.
In North Carolina, a first degree murder conviction can carry the death penalty.
"It appears to me there was evidence to bring a first degree premeditated murder case," Special Attorney General Mike Dodd argued.
He pointed out that the case met all seven stipulations under North Carolina law for a first degree murder prosecution.
However, a grand jury instead opted in 2016 for a second degree murder charge.
Defence lawyers David Freedman, for Mr Martens, and Douglas Kingsbery, for Ms Martens, delivered oral arguments which challenged the fairness of the August 2017 trial in Davidson County.
The appeal was heard before Chief Judge John Tyson, Judge Valerie Zachary and Judge Allegra Collins at the appeals courthouse in downtown Raleigh.
The defence teams said the prosecution never properly challenged the argument that the father and daughter acted in self defence.
Also cited by the defence teams was the decision by the trial judge to refuse to allow contested statements by Mr Corbett's children, Jack and Sarah, to be entered into evidence.
They also objected to the omission of other evidence which they claimed would have bolstered the defence cases.