Hamburg's mayor, Olaf Scholz, lays flowers Saturday at a makeshift memorial in front of a supermarket where a man killed one person and wounded five others in a knife attack Friday. (Paul Weidenbaum/AGENCE FRANCE-PRESSE VIA GETTY IMAGES)

 The 26-year-old man accused of carrying out a stabbing rampage Friday at a Hamburg supermarket had been reported to security forces as a radicalized Islamist, but he also suffered psychological problems, police said Saturday. 

Authorities had not believed that the man, a Palestinian from the United Arab Emirates, posed an imminent threat, they said. But Friday’s knife attack left a 50-year-old man dead and five people injured, Hamburg police said. A sixth person was injured attempting to overcome the suspect, who fled but was arrested at the scene in the Barmbek neighborhood of the northern German port city.

Hamburg police said that the man, whose name they did not release, was acting alone and that his motive remains unknown.

Still, the attack instantly renewed a political debate over Germany’s asylum policies and whether a harsh enough line has been taken against criminals and migrants whose requests for asylum are turned down. It also shed light on the nexus of violence and psychological distress, an overlooked consequence of the torturous quest for asylum, advocates say.  

A commission is probing the case, and a psychological investigation is being conducted before charges — likely murder and attempted murder — are filed, said Jörg Fröhlich, Hamburg’s state prosecutor. Officials said the man’s asylum request had been rejected but that his deportation had been delayed because he did not have identity papers. They said he was living in a refu­gee home in Hamburg.

“On the one hand, there are indications that he acted based on religious Islamist motives, and on the other hand, there are indications of psychological instability,” said Andy Grote, the interior minister of Hamburg, at a news conference Saturday.

The man’s only run-in with police came in April, prosecutors said, after he was caught shoplifting. The case was dismissed. Before that, a friend of the man had alerted security officials to his possible radicalization, said Torsten Voss, head of Hamburg’s state intelligence agency. But Grote said the threat level was considered low; specifically, he was classified as an Islamist, not a jihadist.

The question of how a man known to authorities slipped through the cracks is politically vexed, coming less than two months before an election in which Germany’s center-right chancellor, Angela Merkel, is seeking a fourth term. It carries echoes of an attack in December 2016 when a failed asylum seeker, Anis Amri, drove a truck into a Christmas market in Berlin. The Islamic State claimed responsibility for that attack.

“What else has to happen in order for politics and society to finally rethink?” asked Alexander Gauland, one of two leading candidates for the far-right Alternative for Germany party , which has fallen in the polls after a string of strong showings in state elections last year.

Merkel’s center-left challenger, Martin Schulz of the Social Democratic Party, has also criticized the chancellor’s reaction to the refu­gee crisis that brought scores of asylum seekers to Germany beginning in 2015. Schulz said Merkel’s open-door policy came without proper monitoring and consultation with other European states.

Merkel, who is on vacation, released a statement expressing grief for the victim and promising, “The act of violence must and will be clarified.”