Eyewitnesses said Muhammed Riyad – the name is circulating in Germany although not yet confirmed – swung the axe into the stomach of one of his victims in a bid to disembowel him.
According to the local newspaper in Ochsenfurt- where the would-be assassin had lived with a foster family for the last two weeks of his life – it was the 31-year-old boyfriend of the Hong Kong victims’ daughter who was most gravely injured.
The mother suffered severe head wounds as did her husband.
It comes as ISIS released a clip claiming to show the Germany axe attacker pledging allegiance to the terror group.
In the clip, the alleged attacker said: “I’m a soldier of the caliphate. I will lead a martyr attack. in Germany, the time has arrived.
“Soldiers of the caliphate are coming to you. They will slaughter you in your homeland.
“Know this, that the Islamic State is powerful and has your parliaments in its sights.
“I would advise you not to forget the spectacular attacks in France. I will fight you so long as I live and I will slaughter you with this knife and I will cut through your throats with this axe.”
As three of his four victims battle severe injuries in the University Clinic of Wuerzburg, police began to draw a picture of the disturbed teenager who seems to have radicalized himself into murderous Islam in just a matter of weeks.
The Afghani, 17, was one of 70,000 unaccompanied refugees living in Germany.
He arrived two years ago as a 15-year-old and appears to have lived a blameless life until his savage attack on defenceless train travelers.
He boarded the train in Ochsenfurt at 8.00pm on Monday for the hour long journey to Wuerzburg.
He sat next to the Hong Kong family and then pulled a knife and an axe from a bag and began hacking at them.
Someone pulled the emergency cord when the train was in the Wuerzburg suburb of Heidingsfeld, just behind a quiet street called Roethenweg.
Melanie Göttle and Günter Karban heard screams in their garden shortly after 9.15pm.
Their garden borders on the tracks and the pair ran out through a narrow gate to try to aid the wounded who were screaming.
“The paramedics brought the injured on stretchers through our garden to the ambulances,” said Melanie.
She, her husband and neighbours helped as best they could, bringing out blankets and towels.
“We gave them hot sweet drinks before police sent most of us back into our homes,” said Melanie.
“The Asian man looked quite terrible,” added Melanie.
“I hope so much that he survives the attack.”
She didn’t see the gunman. But a neighbour told her that the Afghan with an axe in hand was shot and killed near their home at 11.00pm.
Apparently Riyad chose that train because it was often used by a woman social worker who had helped him in the past.
The woman was on the train, and called police when she saw what was unfolding.
He fled the train shortly afterwards and was gunned down by a police commando squad minutes later. His body lay In a field until early on Tuesday morning when it was removed by police.
The axe he used in the attack was found nearby.
As police began the hunt for clues to his mindset a self-painted ISIS flag, along with a handwritten text in Pashtun praising holy war, were found in the bedroom of his foster home in the small Bavarian town of Ochsenfurt.
There were also books in English and German about Islam found in his room.
There was also a written farewell to his father among his possessions. He had been placed with a couple just two weeks ago after living for nearly two years in a hostel run by the Catholic Kolpingwerk charity.
Neighbours in the street adjacent to the centre recalled a “confused” young man who never marked himself out as a fanatic of any stripe.
“He always looked worried” recalled Hannelore Lenz. But then the Afghanis here often did. The government changed the rules about offering them asylum and they were always perpetually worried about if they were going to be allowed to stay.”
Another who would not give her name said: “The relationship with the refugees was always harmonious here.
“I do remember seeing this young man around town – not very tall, very intense dark eyes, always a little troubled looking. But I never thought him capable of this.”
People in Ochsenfurt said he was seen in a nearby mosque on “high days and holidays” but was by no means regarded as deeply religious.
Police have refused to reveal the names of his foster parents but they are known to be worshippers at the Catholic Kreuzkirche in the centre of the town and registered with the charity that had looked after the youngster to provide a home for him.