Christopher Dunne (17) has been found guilty at the Central Criminal Court of the murder of Alan Higgins for his mobile phone.
The jury of eight men and four women deliberated for just over three hours before reaching a unanimous verdict. Dunne was also found guilty of stealing Mr Higgins's phone and a sum of cash.
Dunne, of Millwood Villas, Kilbarrack, Dublin, had denied murdering Mr Higgins (17), of Carraroe Avenue, The Donaghies, Donaghmede, on October 13th, 2002, outside the UCI cinemas, Coolock.
He also denied stealing the victim's mobile phone and a sum of cash on October 12th, 2002.
Surrounded by family, Alan's mother and sister, Miriam and Catriona Higgins, wept as the verdict was delivered.
Christopher Dunne's father, Patrick, hugged his son from across the bench accompanied by his daughter, Pamela, as the verdict was returned.
Mr Justice Abbott thanked the jury and excused them from service for the next 10 years. The judge said he needed time to consider all elements of Dunne's case before sentence. He said he would have to take into consideration the age of the convicted youth.
Dunne's two accomplices on the night Alan Higgins lost his life, Michael Maher and Anthony Whelan, had pleaded guilty last week at the Central Criminal Court to the manslaughter of the schoolboy.
Mr Justice Abbot said Dunne would be sentenced alongside Maher and Whelan. Dunne was remanded in custody until October 26th.
During the 10-day trial, the jury heard that Mr Higgins had just kissed his girlfriend goodnight when he was set upon by Dunne, Maher and Whelan. The convicted youth stabbed Mr Higgins three times for his mobile phone and wallet outside the UCI complex in Coolock.
The State Pathologist, Dr Marie Cassidy, told the court that Mr Higgins died from haemorraging and shock due to a stab wound to the chest.
Dr Cassidy said he had suffered considerable blood loss. So much had been lost that he developed a blood clot, and blood was flowing from his wounds.
Dr Cassidy said Mr Higgins suffered three stab wounds to the chest, with the most serious penetrating the lung.
"The knife had gone inwards and upwards from back to front, penetrating his third and fourth ribs and then into his lung," Dr Cassidy said.
The upper lobe of the right lung had been removed by surgeons when they were trying to save his life, she added.
The fatal wound which was found in the removed part of the lung was 3 cm long and cut through the lung, the State Pathologist said.
Dr Cassidy was shown a steak knife in court and said: "Yes, that was the knife I was shown" in October 2002.
"Given the dimensions of the knife and the wounds to the body, a knife like this could have caused the stab wounds. A knife like this would require only moderate force to penetrate the body cavities," she said.
Dr Cassidy said Mr Higgins had suffered from a severe form of leukaemia when he was four years of age. In his medical notes from Temple Street Hospitalhe was in complete remission in 1989.
She said the schoolboy had completely recovered from the illness and was not suffering from leukaemia when he was fatally stabbed.
He had also suffered blunt force trauma to the head and arms. "The wounds to his face suggest Alan Higgins received a few punches to the face," she said.
The position of the fatal wound was in an area normally protected by the arm. "This suggests he had his arm raised in self-defence when he was attacked," Dr Cassidy said.