US prosecutors have launched a determined bid to uphold second-degree murder convictions for Thomas and Molly Martens and ensure they serve 20 to 25-year prison sentences for the brutal killing of Irish father-of-two Jason Corbett (39).
The father and daughter were convicted of battering the Limerick-born businessman to death with a metal baseball bat and a brick as he slept in his luxury home in North Carolina in August 2015.
Martens (69) is a retired FBI agent while his daughter (35), who was Mr Corbett's second wife, suffered from a lengthy history of mental health problems.
North Carolina Attorney-General officials have lodged a 96-page submission to the state's Supreme Court seeking to have a Court of Appeal ruling overturned and the original second-degree murder convictions upheld.
The Court of Appeal ruling on February 4, by a majority 2-1 decision, granted Thomas and Molly Martens a retrial.
Two judges found that decisions of the trial judge were potentially prejudicial to the defendants and may have undermined their ability to receive a fair trial.
That appeal ruling was immediately challenged by the North Carolina District Attorney's Office and the Supreme Court will now rule on either upholding the original convictions or granting a retrial, most likely for late 2021 or early 2022.
In the submission, North Carolina prosecutors have directly addressed the two key issues which, in the opinions of two Court of Appeal judges, raise concerns about the original trial.
The third Court of Appeal judge strongly disagreed with her colleagues and ruled that the trial magistrate, Judge David Lee, had conducted both a fair and balanced trial.
Prosecutors have defended the decision of Judge Lee to not allow into evidence statements taken from Mr Corbett's two children, Jack and Sarah, by North Carolina social services.
Judge Lee did not allow these statements because they were directly contradicted by statements made by the children just weeks later on their return to Ireland from North Carolina.
The Martens have both insisted they acted in self-defence that night - despite the fact neither had suffered so much as a scratch, cut or bruise at the scene. In contrast, Mr Corbett's skull was so badly crushed that a pathologist subsequently could not accurately count the number of blows inflicted.
Judge Lee also did not allow into evidence a statement from Thomas Martens in which he recalled an alleged conversation with Michael Fitzpatrick, Mr Corbett's first father-in-law. Mr Fitzpatrick, shortly before his death, made a sworn deposition to an Irish solicitor denying he had ever made any such statement to the former FBI officer.
It also emerged Thomas Martens initially said the disputed statement was made at an event in the US that Mr Fitzpatrick had not attended.