A "love triangle" murder trial has heard a man is accused of stabbing his former partner's lover to death.
Keith Connorton is accused of stabbing Graham McKeever as the 29-year-old came to the aid of Mr Connorton's former partner.
Mr Connorton, of Deerpark Avenue, Tallaght, was arraigned before the Central Criminal Court yesterday, charged with murdering Mr McKeever in an apartment at that address on February 18, 2017.
Dressed in a checked shirt, he stood and pleaded not guilty to the charge.
A jury of nine men and three women was sworn in to hear the trial and Brendan Grehan SC opened the case on behalf of the prosecution.
He said that there was one other person present when Mr McKeever met his death: the mother of Mr Connorton's child.
Claire McGrath, who was 28 at the time, had been in a relationship with the accused for three years, and they had been living in that apartment on Deerpark Avenue.
However, it is the prosecution's case that she had effectively broken up with Mr Connorton about six months before this incident.
This was because she believed that the accused was unable to kick his drug habit.
She began seeing the deceased, the court heard.
"So you are dealing with somewhat of a love triangle, if I can put it that way," said Mr Grehan.
"Mr McKeever was invited to stay over at her apartment on the night."
He said that the deceased was in bed at the apartment when, sometime before 4.30am, Ms McGrath heard a noise.
"She got up to investigate and discovered Mr Connorton was in the apartment. It appears he had a key," he said.
"The prosecution case is that Mr Connorton became aware that Mr McKeever was in the apartment and Ms McGrath was, in effect, being threatened by Mr Connorton, who had armed himself with a knife from the kitchen.
"When Mr McKeever came to her aid, he ended up getting fatally stabbed in the chest."
He told the jury that he had been stabbed a number of times, "significantly", in the back.
Mr Grehan also understood that the accused would be asserting self-defence.