The trial has heard from a North Carolina pathologist
Jurors have been shown the baseball bat and blood-stained paving brick used to inflict fatal head injuries on Limerick man Jason Corbett.
The prosecution case in the murder trial in North Carolina is set to continue for at least another three days.
The trial began last Tuesday and is expected to last between four and six weeks.
Jason Corbett's wife Molly Martens and her father Thomas Martens deny the second degree murder charge against them.
Ralph Riegel is southern correspondent with the Irish Independent.
He says Davidson County crime scene examiner, Lt Frank Young, opened two brown paper evidence bags to show the items to the jury.
"The jury got to see the baseball - interestingly, it is not an adult baseball bat it's a Little League bat and it's designed for teenagers who want to play in the Little League aspect of baseball here in the United States".
He also described evidence heard from the pathologist.
"This was quite a serious, prolonged and ferocious attack on Mr Corbett, borne out very much by what Dr Craig Nelson - the pathologist - said.
"He said he couldn't even determine the precise number of blows that Mr Corbett suffered, especially to his head, because there were multiple blows...to the rear of Mr Corbett's skull".