A man who was fatally stabbed while attempting to protect a boy at a train station has been identified after the first of his alleged assailants faced court.
Aidan Becker, 22, died at Mernda Railway Station in Melbourne's northeast on Friday evening after intervening to protect a 14-year-old boy from a group of four alleged teenage attackers.
Mr Becker, a security guard who was off-duty at the time, has been hailed a hero by members of the public, including Liberal MP for La Trobe Jason Wood.
"Tragic murder of a true hero who stepped up to protect a 14-year-old boy during a youth gang knife attack," Mr Wood said in a post to social media on Sunday.
"I feel really sorry for his family and friends and also angry why he lost his life when he was trying to protect others."
Police allege Mr Becker, whom they have not referred to by name, was one of several passers-by who stepped in to protect the 14-year-old.
He tried to walk away with the boy but was subjected to a "savage" attack involving punching, kicking and the use of blades, Homicide Squad inspector Nigel L’Estrange said on Saturday.
Mr Becker suffered life-threatening injuries and was treated by paramedics but died at the scene.
Four male teens were arrested at the scene, three of whom have been charged with murder and armed robbery.
The eldest, Mike Pikos, 18, appeared before Melbourne Magistrates Court on Sunday morning but was not required to speak during the short hearing.
Magistrate Steven Raleigh was told it was the teen's first time in custody and he would be a vulnerable prisoner due to his age and appearance.
No other information was given during the brief session and there was no application for bail.
A 16-year-old from Whittlesea and a 17-year-old from Geelong were also charged with murder and armed robbery.
A 17-year-old from the City of Yarra remained under police guard in hospital and had not yet been charged on Sunday.
"This is just a tragic situation where our victim here is just a good Samaritan who was trying to do the right thing," Det Insp L'Estrange said.
"He's intervened, tried to protect this 14-year-old schoolboy, hasn't been aggressive at all, tried to remove him from the scene, and as a result of his interaction, he's now lost his life."
Health Minister Mary-Anne Thomas said her thoughts were with the victim's family while pointing to recently introduced youth crime laws that could result in juvenile offenders being dealt harsher punishments for serious crimes.
But opposition police spokesman Brad Battin and Mr Wood linked the incident to Labor's failure to tackle the issue and remove machetes from the streets.
Pikos was remanded in custody and will return to court on June 24.
