Five months after his death, the wife and father-in-law of Jason Corbett have been charged with his murder.

Mr Corbett, a Limerick native and father-of-two, was found with fatal head injuries, allegedly from a baseball bat, at his home in North Carolina on August 2 last.

His wife Molly Martens and her father Thomas, a former FBI agent, were both charged with second degree murder and voluntary manslaughter by a grand jury in the state yesterday. A trial against the pair will go ahead at a later date.

Police were called to the home of Mr. Corbett and Ms. Martens in the early hours of August 2 following reports of a domestic disturbance. According to police reports, Mr Thomas Martens told the 911 dispatch operator who took the call that "he had been in an argument with his son-in-law and that he had struck him with a baseball bat".

However the Martens family allege that the actions against Mr. Corbett were "necessary and justified," with Ms. Martens' uncle Ernest saying he was confident the pair would be "exonerated."

There are "no finer people you could meet" than the Martens, he said on Newstalk Breakfast this morning, adding that the pair plan to plead not guilty.

Mr. Corbett married Ms. Martens after moving to the US in 2011 and employing her as his nanny.

His first wife and the mother of his two children Jack and Sarah, Mags Corbett, died after suffering an asthma attack in 2006.

Mr. Corbett's sister Treacy Lynch and her husband David – who are currently the legal carers of David's two children after a custody battle with Ms. Martens – travelled to the US for the grand jury decision hearing yesterday.

"The family see it as a start," a source close to the Corbetts said of yesterday's development.