Joseph Joyce was convicted by a jury in June of murdering 18-year old John Paul McDonagh, who sustained a fatal leg wound during a 'street battle' in Enniskillen in April 2020.
During the trial, the jury of eight men and four women were shown footage of the fatal incident, which occurred outside Joyce's Coolcullen Meadows home.
Following a row between Joyce and the members of the McDonagh family - who lived at Drumawill Gardens in the same area of Enniskillen - three members of the McDonagh family armed themselves and made their way to the Joyce's home.
In the footage, Joyce is seen standing on the street outside his home.
Brandishing a slash-hook in one hand and plastic bottle filled with ammonia in the other, the footage captured Joyce engaging in what the Crown described as a "street battle" with Gerard, John and Jimmy McDonagh.
The footage also captured Joyce administering the fatal blow to the back of John Paul McDonagh's left leg.
Despite receiving medical treatment both at the scene and in the South West Acute Hospital, Mr McDonagh passed away on the morning of April 13, 2020.
Following his arrest, Joyce made the case he was acting in self-defence and was protecting his pregnant wife, his home and his children from an imminent attack by the McDonaghs, who threatened to burn his home down.
He also told police at the time that he was sorry for what happened and never intended to kill anyone.
The case was back before Belfast Crown Court today, where Joyce's barrister again apologised on his client's behalf for the loss of life.
Des Fahy KC told Mr Justice Rooney: "Joseph Joyce is profoundly sorry for what happened and for causing the death of John Paul McDonagh. It should not have happened and his remorse is both genuine and sincere."
Saying Joyce acted with "excessive self-defence" on the afternoon of April 11, 2020, Mr Fahy said: "The trouble and violence was brought to his door and he reacted."
Mr Fahy also submitted several characters references written on behalf of Joyce, telling the Judge: "Joseph Joyce is not defined by the verdict of the jury."
Included in the character references were statements from a police officer in Derry who spoke of the "positive affect" Joyce's influence has had on the Travelling Community, and a letter from the Traveller Mediation Services who described him as a "peacemaker" regarding family disputes.
Crown barrister Barra McCrory KC urged Mr Justice Rooney to take into account several "aggravating factors" ahead of sentencing.
These, he said, including Joyce arming himself with the scythe-like weapon and a bottle of ammonia, "willingly engaging in the street battle" and absconding from the scene.
Mr McCrory also asked the Judge to consider "the impact on Mrs McDonagh, who witnessed the killing of her son."
Joyce - with an address at Clon Elagh in Derry - is due to be sentenced for murdering John Paul McDonagh, wounding the deceased's brother Gerard McDonagh, possessing two offences weapons - namely the slash hook and bottle of ammonia - and a charge of causing an affray.
Mr Justice Rooney said he would sentence Joyce next week.
Joyce's wife Ellen (31) is also due to be sentenced for a common assault committed on the same day.
In addition, several members of the McDonagh family are due to be sentenced on a separate date for a variety of offences arising from the same incident.
This includes Gerard McDonagh who was convicted by a jury in a separate trial of attempting to cause grievous bodily harm to Joseph Joyce, possessing an offensive weapon and affray.