The "only reasonable" verdict to be reached in the trial of a teenager accused of murdering Mr Alan Higgins "is one of murder", a jury has heard at the Central Criminal Court.
Mr Paul Green, prosecuting, said the verdict of murder "is the only reasonable conclusion to be drawn".
The accused, who cannot be named for legal reasons, denies murdering Mr Higgins (17), of Carraroe Avenue, The Donaghies, Donaghmede, on October 13th, 2002, outside the UCI cinema, Coolock, Dublin.
The accused also denies robbing the victim's mobile phone and a sum of cash on October 12th, 2002.
Mr Green said Mr Higgins' death was a "great tragedy".
"Likewise it's a tragedy that the accused is before the Central Criminal Court for actions that occurred when he was 15½. I suggest to you that the accused is, without a shadow of doubt, guilty of unlawful killing."
Mr Green told the jury they should look at the evidence in the case. On the night Mr Higgins was fatally stabbed, he and the accused "were two young people who congregated at the UCI in Coolock. They were both leading parallel lives," Mr Green said.
Mr Higgins met his girlfriend and played a few "innocent video games and pool with her and her friends".
The deceased, Mr Green said, ended his evening early because he "wanted to put in a night's sleep before doing a day's work in his part-time job".
At the same time as Mr Higgins was with his girlfriend, the accused was in the company of two friends outside the UCI complex. These two friends, Mr Michael Maher and Mr Anthony Whelan, were to become the accused's "accomplices" in crime, Mr Green said.
The accused and his two friends "kicked off the day" Mr Higgins died by getting an "irresponsible adult to buy them alcohol".
At 8 p.m. that evening "the accused started to make a serious nuisance of himself, which is putting it at the most benign."
The UCI area was the accused's "war zone".
Mr Green said the accused and his accomplices came across three different groups that evening, and robbed a rucksack, cans of lager and two mobile phones in the vicinity of UCI.
Just a few minutes after Mr Higgins kissed his girlfriend goodnight, the accused and his two friends came across him.
It was three against one. "Alan Higgins was on the ground. The accused had the upper hand," Mr Green said.
"Notwithstanding the fact that Alan Higgins was on the ground, the accused felt it was necessary to produce a knife from his back pocket and stab Alan Higgins, not once, but three times."
Mr Green told the jury that the accused had allegedly admitted to the murder of Mr Higgins in his various statements to gardaí. He said the accused, in his own words, said: "I stuck him with the knife and he rolled off."