A 17-year-old boy who stabbed a German student to death in Dublin has been sentenced to seven years detention for murder.

Mr Justice Barry White described the teenager as the ringleader in a fatal attack on Thomas Heinrich in Rialto on 1 December 2012.

His co-accused, Wesley Kelly (20) of St Anthony's Road, Rialto has been jailed for 6.5 years after he pleaded guilty to the manslaughter of the student.

Heinrich (22) and his friend Robert Rinker (25) were stabbed in the early hours of the morning after getting into a row with some teenagers in Rialto.

Robert Rinker received multiple stab wounds but survived the attack.

The two German students had been attending Griffith College while on an Erasmus year in Dublin.

The 17-year-old, who cannot be named, was convicted of Thomas Heinrich's murder by a jury at the Central Criminal Court but will not serve a mandatory life sentence because he is a minor.

He and Wesley Kelly were given a five year custodial sentence for the serious assault on Mr Rinker.

Tragic repercussions

Mr Justice White told the two young men in the dock, who have no previous convictions, that their actions have had tragic repercussions for many, particularly Thomas Heinrich's parents whose suffering is likely to last the rest of their lives.

He also told them that they had blighted their own lives and would henceforth be known as killers.

The judge said he could not consider deterrent sentences because his 'strong views' on their merit in tackling the prevalence of knife crime was not supported by many judicial colleagues.

The two young men looked down at the floor as their sentences were imposed while some of their family members broke down in tears.

Difficult chapter

Speaking to reporters after today's sentence, Thomas Heinrich's father said he and his wife Alexandra were glad to have closure from this 'difficult chapter'.

He described his only son as a 'bright young man, very sociable... helpful to people around him and very much against violence in all ways':

Alexandra Thon Heinrich said they had received great support from the Irish justice system.

They called for something to be done about knife crime, but said they do not believe their son's killing reflects on Ireland.