The jury of a Derry man accused of murdering his pregnant former girlfriend were told on Tuesday night they cannot acquit the suspect.
A trial judge said if it was accepted Stephen Cahoon was provoked in to what he did, or intended to cause less injury to Jean Quigley, then the charge could be reduced to manslaughter.
Ms Quigley, 30, was beaten and strangled at her home in Cornshell Fields, Derry, on July 26th last year.
Mr Cahoon has admitted killing the pregnant mother-of-four but denies murder. The 37-year-old from Harvey Street, Derry, opted to have his trial in the Republic after he was arrested in Donegal.
The victim's devastated mother Emma McBride sobbed in court as defence barrister, Michael O'Higgins, described her daughter as a good person and mother with a good set of friends.
He admitted Mr Cahoon was less charismatic, but stressed witnesses had told the court Ms Quigley was hot tempered, had a sharp tongue, and could be aggressive after taking alcohol.
Mr Cahoon maintains after the former couple had sex, she shouted at him that the baby was not his and he snapped and strangled her.
In charging the jury at Dublin's Central Criminal Court, Mr Justice Patrick McCarthy stressed the prosecution had to prove beyond reasonable doubt that the defendant had intended to kill or cause serious injury at the time.
"The accused has said he did not intend to kill or cause serious injury... he merely intended to stop the deceased from saying offensive things to him," said the judge.
"He accepted this could cause injury but that there was no intention to cause death or serious injury."
But Patrick Marrinan SC, for the state, told the jury to keep in mind the nature of the bruising found on Ms Quigley's body and how Mr Cahoon had locked the door from the outside after he strangled her.
'Right verdict'
His barrister, told the jury manslaughter was the right verdict for the case.
Mr O'Higgins claimed any man told a baby was not his would have been confused and potentially angry. He said his client did not know what to believe that night.
Mr O'Higgins added that when Mr Cahoon left Ms Quigley he knew in his heart she was dead but wanted to believe otherwise.
Mr Cahoon is making legal history as the first person to face a jury in the Irish Republic for a non-terrorist related offence in Northern Ireland.
Under the Criminal Law Jurisdiction Act of 1976 suspects can be tried in the Republic for alleged offences in Britain or Northern Ireland.
Last November Gerard Mackin, of Belfast, became the first person to be convicted by a Dublin court for a murder carried out in Northern Ireland.
Mackin was jailed for life by the non-jury Special Criminal Court after he was found guilty of killing Belfast taxi driver Eddie Burns in the city in 2007.
© Press Association