A 16-year-old boy, who stabbed a 21-year-old man to death at a Halloween bonfire in Dublin just over a year ago, has been given six years' detention with 18 months suspended.

The boy, who cannot be identified for legal reasons, pleaded guilty to the manslaughter of Lorcan O'Reilly at the Oliver Bond Street flats in the early hours of 1 November 2015.

Mr O Reilly's family said they were robbed that night of a happy, kind and thoughtful son and brother.

Gardaí said they met a wall of silence during the murder investigation and had to arrest 20 people before the killer was caught.

Mr O'Reilly was attacked and stabbed to death by a 14-year-old at the bonfire in 2015. The boy had earlier been seen swinging a hurley as he arrived at the scene at 2.40am that morning.

The boy got into a row with Mr O'Reilly and the court heard he shouted at him: "You don't know who my dad is … You don't know who I am."

Mr O'Reilly took the hurley from him and replied: "I don't care. I'm not letting a 14-year-old talk to me like that."

The boy left, came back with a knife four minutes later and stabbed him in the face and chest.

Detective Inspector Paul Cleary testified that even though there were 23 youths at the Halloween party, the gardaí struggled to gather witness statements and 20 people had to be arrested.

He also said gardaí had serious concerns about "the safety and well-being of witnesses" in the case.

The boy was charged with murder but pleaded guilty to manslaughter.

Mr Justice Patrick Mc Carthy said it was a serious offence rendered far more serious by the fact that he brought the knife to the scene. He said the appropriate sentence was six years' detention with 18 months suspended.