The 40-year-old suspect, arrested after trying to flee the scene, was a man from Eritrea in Africa – a fact seized upon by far-right elements. It was later revealed he had undergone psychiatric treatment.
“These people are the collateral damage of the totally moronic German culture of welcome,” Udo Hemmelgarn, an AfD MP tweeted. “Now even children are being murdered.”
Alice Weidel, the AfD’s leader in the German parliament, said the “act of cruelty” was a new low, blaming “the limitless Welcome Culture”, a reference to Chancellor Angela Merkel’s move to open the borders to an oncoming wave of refugees from the Middle East in 2015.
On Tuesday it emerged the man had lived in Zurich, Switzerland since applying for asylum in 2006, where he had a wife and three children and had been granted a settlement permit.
But Weidel said this was no reason to move on. “The limitless Welcome Culture leads to an ever-more threatening security situation throughout Europe,” she tweeted.
Prosecutors were seeking to charge the man with murder and attempted murder: he had also tried to push a 78 year-old woman onto the tracks before fleeing.
On Tuesday authorities said the man had been the subject of an arrest warrant from Swiss police for a recent series of violent incidents in Zurich, including threatening a neighbour with a knife. He had also recently received psychiatric treatment.
They had no evidence of radicalisation or an ideological motive.
They also found no connection to an incident last week when a 26 year-old man from Eritrea was left seriously wounded by a drive-by shooting in the small West German town of Wachtersbach.
Public prosecutor Alexander Badle had said there was a “very clear xenophobic motive” to that attack, by a 55-year-old German man later found dead in a car in a nearby town, who left a letter that reportedly contained a padlock with a swastika and the SS motto and was well-known to hold far-right beliefs.
Racial issues have been a hot topic in recent weeks in Germany. The Bild tabloid ran a story about two kindergartens in Leipzig who said they would no longer serve pork or gelatin-containing gummy bears, out of respect for Muslim students. Police were sent to protect the schools after an angry online backlash.
In early June a man described as having neo-Nazi ties was arrested on suspicion of murdering Walter Lubcke, a local politicians from Angela Merkel’s CDU party.
And a week ago the Left party reported there had been an email bomb threat at its Berlin headquarters from far-right extremists.
A week ago a man killed a 34-year-old woman in Voerde by pushing her in front of a train. In this case the suspect was reportedly born in Germany of Serbian background and had been caught at the scene by an Iraqi immigrant, who held him until police could arrive.
Interior minister Horst Seehofer interrupted his holiday to meet security authorities on Tuesday.
He said he was “deeply shocked” by the Frankfurt murder, and recent events had created a sense of “erosion of values” although crime was in fact falling – as was immigration.
He defending Germany’s policy on asylum seekers, saying “immigration must be controlled and limited, but those who need protection, that is the moment of humanity, they must be given protection, and that’s what we do in Germany more than any other country in Europe”.
He said he had discussed more police presence and video surveillance at railway stations.
Deutsche Welle, the German public international broadcaster, editorialised that the country was in shock, and defended the widespread reporting of the suspect’s nationality.
“Since the summer of 2015… some Germans feel a deep sense of anxiety, a lack of security and fear,” DW’s editor-in-chief Ines Pohl wrote. “There is a debate that can only be had if we know the detail that the perpetrator is from Eritrea.”
But Constance von Bullion in the Suddeutsche Zeitung commented that anger over the incident could “poison an entire society”.
“Migration is identified as the mother of all problems… and the fear of the black man is given new fuel,” von Bullion wrote.
After years of emotion and agitation it was time for calm, she wrote, otherwise the country could “break apart”.
Nick Miller is Europe correspondent for The Sydney Morning Herald and The Age