A jury will decide today whether Mr Laurence Callaghan (33) is guilty of the murder of Ms Janet Mooney (29) in September 1996 at the flat they shared in Harrington Street, Dublin. Mr Callaghan denies murder but pleads guilty to manslaughter.
He told the jury yesterday he was trying "to put his foot down" after five years in a relationship.
In a late sitting of the Central Criminal Court, the prosecution claimed Mr Callaghan thought his actions were everybody's fault but his own, while the defence said he lived in a different world where his girlfriend's playing of games over a piece of cannabis provoked him into losing control.
Mr Sean Ryan SC, prosecuting, put it to Mr Callaghan: "In all this, you don't think it's all your fault".
The accused man replied that he accepted responsibility for it every day he woke up. "If you read through my statements, you will see something akin to a confession," he said.
Mr Callaghan said Ms Mooney did not plead with him as he attacked her. He agreed that in his statement to gardai he had said: "She was telling me to stop, that I was making noise and that I would attract the neighbours."
He knew she was being sarcastic, he said, because she had no interest in the neighbours of the flat. "Janet did not take any threat from me seriously," he said. "She had no reason to." But on this occasion, "in an unprecedented fashion, I sought to take control of a situation after five years".
So he was putting his foot down, Mr Ryan suggested. "Trying to", the accused man replied.
In his closing address to the jurors, Mr Ryan told them this answer indicated "an intentionality about the whole thing" that raised the issue from manslaughter to murder.
If they were to understand Mr Callaghan's own evidence, what happened was a savage prolonged attack or series of attacks, he suggested.
Mr Ryan said he was not entirely certain Mr Callaghan was accepting responsibility for his role in Ms Mooney's death.
In his closing speech, counsel for the defence, Mr Erwan Mill Arden SC, told the jurors common sense would lead them to understand that Mr Callaghan lived in a different world, a world where "the biggest concern was getting the rent" and where the reality was drunkenness and the fear of becoming sober.
Counsel told the jurors they had to put themselves in Mr Callaghan's shoes, "unsavoury as it may be". The missing cannabis which he believed Ms Mooney had hidden, "the playing-of-games situation constituted a provocation that rendered him mindless and caused him to lose control".
Mr Justice Carney will charge the jurors on the law today.