THREE people questioned over the fatal stabbing of a German student at the weekend have been released without charge and a file is being prepared for the DPP.
However, a fourth person - a teenager arrested yesterday evening - remains in detention at Pearse Street Garda Station under Section 30 Offences Against the State Act 1939.
Twenty-two-year-old Thomas Heinrich, from Munich, was stabbed in his stomach and suffered a severed artery in the attack outside his apartment in Rialto in Dublin's south inner city.
His friend, Robert Rinker (22), from Stuttgart, was also stabbed in the incident in the early hours of Saturday morning.
It is believed the men were attacked after they became involved in a row with two Irish teenagers.
Two young men were questioned at Kevin Street garda station yesterday and their period of detention was extended during the day. A woman in her 40s, the mother of one of them, was held at Pearse Street garda station. The fourth person was arrested last night.
Three were released last night without charge from garda custody while the fourth has been detained overnight. A file will now be prepared for the Director of Public Prosecutions.
The Griffith College student had been expected to return home permanently to Germany in three weeks' time, when his study period in Dublin came to an end.
The incident occurred outside the Herberton apartments on St Anthony's Road, Rialto, at around 5.30am on Saturday.
The two German men were renting accommodation there in an area popular for students from universities throughout Dublin.
Gardai believe the two men who were stabbed were on the balcony of their first floor apartment when two local teenagers walked past on the street below.
Detectives believe words were exchanged between the teenagers and the men on the balcony.
At that point, it is believed that at least two men from the apartment went downstairs and become involved in an altercation on the street with the teenagers.
Gardai are trying to establish if a fight broke out, with some witnesses suggesting the row became physical at that point. After a period, the clash broke up and the teenagers left the scene as the men they were arguing with went back inside.
However, some time later the teenagers came back and there was another confrontation on the street, during which the teenagers produced knives and the two German men were stabbed.
Mr Heinrich lost a significant amount of blood at the scene and was rushed by ambulance to nearby St James's Hospital, where he underwent surgery. However, he was pronounced dead at around 9am.
He was described yesterday as a popular and artistic student who loved music and football.
There were difficulties contacting his parents, with his mother believed to be travelling in England but they were eventually traced and were yesterday travelling to Ireland.
Mr Rinker, who was a friend of the dead man, is in a stable condition in hospital and is expected to survive. He is understood to have suffered a number of slash and stab wounds, mostly to his hands and one to the head.
Both men were students at the MHMK Makromedia School for Media and Communication in Munich and, as part of a post-graduate degree, were obliged to spend their third semester abroad. They chose Ireland, studying international media management at Griffith College.
The scene of the attack remained cordoned off yesterday as an investigation by the Garda Technical Bureau continued. Any witnesses have been asked to contact Kilmainham garda station at 01 666 9700, the Garda Confidential Line on 1800 666 111, or any garda station.
The vicious stabbing took place not far from where two Polish men were killed in a stabbing almost five years ago.
The stabbing took place around 2km from the scene of the February 2008 murder of Polish nationals Pawel Kalite (29) and Marius Szwajkos (27) outside their home on Benbulben Road.
David Curran (20), of Lissadell Green, Drimnagh, was jailed for life for stabbing the mechanics through the head with a screwdriver.