Two people have appeared in court in Dublin charged in connection with the death of Dale Creighton in Tallaght, while two more peole have been arrested.
The 20-year-old was fatally attacked at a pedestrian bridge at St Dominic's Road in the early hours of New Year's Day.
James O' Brien (aged 21) with an address at 12 Avonbeg Drive and David Burke (aged 25) of 6 Village Square, both in Tallaght, were charged with violent disorder under Section 15 of the Criminal Justice Act.
Both were granted legal aid and bail on a number of conditions, and are due in court again on January 16.
Meanwhile gardaí have made two further arrests in the case. A male aged in his 20s was arrested late last night and a second male also in his 20s was arrested this afternoon, both in the Tallaght area.
They are detained under Section 4 of the Criminal Justice Act, 1984 at Tallaght Garda Station.
A third male (20s) arrested yesterday evening remains in Garda custody.
A total of six people have now been charged in relation to the death with three more in garda custody.