A 36-year-old man has been found not guilty of the murder of 16-year-old Josh Dunne at East Wall Road in Dublin last year.
George Gonzaga Bento was also found not guilty of producing a knife in a manner likely to intimidate another and not guilty of assault causing harm to two others.
The food delivery cyclist, who had moved to Ireland from Brazil in 2019, had pleaded not guilty to all charges.
During the trial, the prosecution told the jury that Mr Bento produced a knife during a "stand-off or confrontation" with a man on a moped who had stolen another delivery cyclist's bike.
Josh Dunne and other youths arrived at the scene and got involved in the confrontation.
The jury was told it was accepted that Mr Bento and his friend, Guillerme Quieroz, were acting lawfully in retrieving the stolen bike and were subjected to an unlawful attack by others.
However, the prosecution said that when Mr Bento first produced the knife to the man on the moped, before anyone else had arrived, he was not acting in self-defence, but was being aggressive and "acting the hard man".
The prosecution also argued that the force he used after the teenagers arrived was not reasonable or necessary and neither he nor his friend were being beaten when he took out the knife a second time.
The prosecution has said that there was no need for Mr Bento to stab the first person as he could have just pushed him away.
When he used the knife the second time the attackers were using only their fists, the prosecution said.
The prosecution said Josh was unarmed and there was no need to use a knife against him. They also said that Josh must have seen Mr Bento using the knife against one of his friends and acted lawfully when he punched Mr Bento to defend himself and his friends.
The prosecution said that the third alleged victim had stopped attacking Mr Quieroz when Mr Bento stabbed him in the back and Mr Bento must have known that the use of the knife was excessive and unjustified in the circumstances.
Mr Bento said he was acting in self-defence and was not looking for trouble, but was trying to do the right thing for someone whose bike had been stolen.
His defence lawyers said he had never been in trouble in Brazil or Ireland. They said that when Mr Bento first produced the knife he was reacting to a perceived threat from the man on the moped and pointed out that the Brazilians did not attack the man even though at that point they outnumbered him two-to-one.
The jury was told Mr Bento and Mr Quieroz had decided to leave but were prevented from doing so when the teenagers arrived and attacked them.
The defence said that the use of the knife was justified given the level of assault and the serious risk of injury or even death that the assault posed to Mr Bento and his friend. They had pointed out that the assault happened quickly and that the prosecution's "frame by frame" analysis of CCTV footage was unrealistic.
Read more: What the jury didn't hear
The trial judge, Mr Justice Paul Burns, also told the jury there was no definition of reasonable force; the jury must decide for themselves what was reasonable in the circumstances.
He asked them to consider the nature of the attack, whether weapons were used, the number of attackers and the speed, ferocity and duration. They should consider the "natural shock or fear such an attack would cause. Life is not lived on a frame by frame basis, there is no pause or replay button. A degree of latitude is to be afforded to the victim of an attack."
He said a person defending themselves cannot "weigh out the exact measure" of what is a reasonable action.
He told the jury to consider each of the four counts separately and that any verdict they reach must be unanimous.
In relation to the murder charge there are three possible verdicts: guilty of murder, not guilty of murder but guilty of manslaughter, or not guilty.
The jury verdicts were delivered after just over eight hours of deliberation which began last Friday.
Josh Dunne's family left the courtroom in silence after the verdicts were delivered.
Mr Bento held his head in his hands. He was released from custody shortly afterwards. Members of his family broke down in tears after he was acquitted.
The judge thanked the jury for their service.
Walking free from the Central Criminal Court with his family, Mr Bento said he was relieved and grateful and needed time to process what had happened.
He thanked his legal team whom he said believed him and fought for him and said he now needed to spend time with his family before thinking about the future.
He also said he had said sorry to Josh Dunne's mother "at the beginning and at the end" and hoped that some day she could forgive him for what happened.