WEEK-IN, week-out it's a scene replicated outside every nightclub and pub in the country: it's the early hours of the morning, the venue has closed and patrons have been ushered outside. There's no more booze to be bought or music to dance to.

But people don't go home. Instead, they hang around outside talking, smoking, drinking, looking for a party. Most of the time, it's fairly good-natured if somewhat drunken and rowdy. But sometimes – as we've seen so many times before in this country – it turns violent and young men and women, often in a haze of alcohol and drug-fuelled aggression, start fighting. And occasionally, these fights take a sinister twist and someone ends up dead.

That is what happened in the vicinity of Barcode nightclub in Dublin's Clontarf just after 3am last Sunday morning. Barry Walsh (22), from Park Lawn in Castleknock, had been socialising with a group of friends at the popular nightspot. After they left, Walsh and his friends went to a fast-food restaurant in the Marino Mart area. Back out on the street outside Fairview Park, they became involved in a row with another group of young adults. The other group, from the north inner city, hadn't been to Barcode nightclub that evening but were socialising in the area. The row started, in predictable fashion, for no particular reason at all. Witnesses have given gardaí different accounts of how it started – someone looked at someone else funny, another person bumped into someone, such-and-such was looking for a fight – detectives have been told.

Bleeding and unconscious

What we know for certain is that insults were traded and a scuffle ensued with punches thrown. Walsh and his friends were called "faggots" by the other group but gardaí are satisfied it wasn't a homophobic attack. "They called them faggots but he wasn't attacked because they thought he was gay," said a garda source. "It was just an insult. The same way that someone might call someone a c*** or a p***k. This was not a gay-bashing attack, we are sure of that. It was a row that got out of hand and unfortunately someone got killed."

As the situation began to escalate, Walsh walked away from the unfolding violence. But he was chased by one man who punched him and knocked him to the ground, face first. He was then kicked in the head with considerable force and left lying on the roadway, opposite the Marino College as his attacker ran off. The apprentice plumber lay bleeding and unconscious in the roadway until the ambulance arrived. He never regained consciousness and died at Beaumont Hospital from his head injuries two days later when his life-support machine was switched off.

Well-respected families

On Wednesday, after news of Walsh's death became public, a man in his 20s went to Clontarf garda station with his father and voluntarily provided information about his role in the row that fateful night. Like Walsh, the young man from the Sheriff Street area also comes from a well-respected family. He is the chief suspect for the killing but has not yet been arrested or charged. Behind the scenes, gardaí are interviewing as many witnesses as they can locate as well as studying CCTV footage. It is possible that others may be charged with violent disorder for their role in the attack but detectives have not yet spoken to everyone from the two groups involved, including some young women, as everyone has not come forward despite appeals.

The investigation is understood to be progressing well and the case has drawn parallels with the killing of student Brian Murphy outside Club Anabel in the Burlington Hotel in Dublin in 2000.

Fr Dan Joe O'Mahony, of Laurel Lodge parish in Dublin 15 and friend to the Walsh family, believes there needs to be a major change in young people's attitudes to violence. Walsh is survived by his parents Bernard and Ena, his brother Adam and girlfriend Louise.

"I have been down with the family, they have been heroic. In the face of their devastation, they have chosen to donate their son's organs. That's the type of people they are," he said. "I would like to bring the perpetrators face to face with Barry's coffin. Let them see what they have done. Why is this violence happening in our society? Are we teaching our young people to be violent through television and video games? This is the fourth case where an innocent young man has been beaten to death after a night out. It started with the Anabel killing. We need to change our language. Instead of 'kill two birds with one stone', why don't we say 'feed two birds with one piece of bread'? Something has to change."

Violence in the vicinity of Barcode nightclub is not a new phenomenon. Things reached a peak two years ago, and local residents from the Howth Road, across from Barcode, had several meetings with gardaí who increased patrols in the area at night-time when the club emptied because of several serious assaults. "A young man jumped through a house window to get away from a gang of people pursuing him two years ago. There were increased garda patrols at peak times at first but it didn't continue," says independent TD Finian McGrath who has raised the issue of anti-social behaviour spilling into the area several times in the Dáil.

Mindless bloodshed

"The club should not have a licence, it's far too big to be located in a residential area. I will raise it again in the Dáil next week, it simply should not be there. The residents have been telling me for years it was only a matter of time before there was a tragedy like this. Unfortunately, they were right."

Historically, Fairview Park has witnessed more than its fair share of bloodshed. It was at this location that the brutal beating of student Guido Nasi was carried out in 1999. The Italian teenager was viciously assaulted in an attack which left him paralysed. He was attacked by two youths and suffered a fractured skull after one of the attackers smashed his head with a beer bottle. Nasi has never walked or talked since the incident and can only type with the aid of three functioning fingers.

But it was the brutal killing of a gay man in 1983 in a homophobic attack that really put Fairview Park on the map for all the wrong reasons. At the time, the northside park was a popular gay pick-up point at a time when homosexual acts were still outlawed. Declan Flynn (31), from Dublin, was unlucky enough to come into contact with a gang of teenagers who had been frequenting the park with the sole purpose of "queer bashing". He died in a vicious and sustained attack and the killing prompted the country's first Gay Pride march.

Some 26 years on, and again the community is numbed by the mindless violence in its midst. "People are afraid to let their young people out at the moment because of this," adds Fr O'Mahony. "The saddest thing is that this weekend, there'll be more people outside nightclubs starting fights. When do we say stop?"