A 29-year-old man who killed a teacher and injured 14 children after driving his car into a crowd in Berlin on Wednesday had a history of suffering from paranoid schizophrenia and was probably intending to kill or injure, German authorities say.

“There are no clues pointing to a terrorist motivation behind this deed, and we can also rule out that it was an accident”, said the spokesperson for the Berlin public prosecutor’s office, Sebastian Büchner. “It was probably a deliberate act.”

The Berlin prosecutor said the German-Armenian man’s history of mental health problems meant he was “likely” not legally responsible for his actions and would instead be placed in psychiatric care.

A teacher died and 14 children on a school trip were injured when the German-Armenian driver steered his silver Renault Clio on to the pavement of a busy shopping mile at about 10.30am local time (0930 BST) on Wednesday. After driving back to the main road he crashed into the shopfront window of a cosmetics store.

He fled into a sports store, where shoppers restrained him until police arrived. One witness told Der Spiegel magazine the man had been in a confused state: “He repeatedly asked for help.”

The crash occurred on Tauentzienstrasse in Berlin’s Charlottenburg district, adjacent to Breitscheidplatz square, where a rejected Tunisian asylum seeker with Islamist links drove a hijacked truck into a crowded Christmas market on 19 December 2016, killing 12 people and injuring dozens of others.

Berlin’s mayor, Franziska Giffey, told the broadcaster RBB on Thursday that the previous day’s incident had “ripped open deep injuries and trauma”.

Police investigators were trying, with the help of a language mediator, “to find out more from the partially confused statements he is making”, she said, adding that information was pointing to the incident having been deliberate.

In a statement on Tuesday night, the German capital’s interior senator, Iris Spranger, said latest information about the driver had made the incident look like “a rampage by a really seriously psychologically impaired person” .

Spranger rejected initial reports that a written statement had been found in the driver’s car that could have pointed to a politically or religiously motivated act.

While police found a poster in the car that criticised Turkey for its role in the Armenian genocide during the first world war, it was unclear whether it belonged to the driver or his sister, the registered owner of the vehicle.