The 18-year-old gunman who killed nine people in Munich was obsessed with mass shootings but had no known links to the Islamic State group, German police say.
Written material on such attacks was found in his room, and Munich’s police chief spoke of links to the massacre by Norway’s Anders Behring Breivik.
The gunman, who had dual German-Iranian nationality, later killed himself.
His name has not been officially released but he is being named locally as David Ali Sonboly.
He has also been referred to as Ali David Sonboly, or David S.
He had an illegally held 9mm Glock pistol and 300 bullets in his rucksack.
Police do not yet know how the weapon was acquired, but said he had no permit for it and the serial number had been obliterated.
They are investigating whether he may have lured his victims through a Facebook invitation to the McDonald’s restaurant where he launched his attack on Friday evening.
Friday evening’s attack at the Olympia shopping mall also left 27 people injured, including children. Ten of them are critically ill, including a 13-year-old boy, police say.
Seven of the dead were teenagers. Three victims were from Kosovo, three from Turkey and one from Greece.
Police say the Munich-born gunman had been in psychiatric care, receiving treatment for depression.
Authorities are also checking reports that he may have been bullied by his peers, Interior Minister Thomas de Maiziere said.
“We are in deep mourning… we share your grief,” said Chancellor Angela Merkel after chairing a meeting of the national security council.
Flags are to be flown at half-mast across Germany.
People could be seen laying flowers and lighting candles outside the mall on Saturday. One placard left there simply asked “Why?”
Munich police chief Hubertus Andrae said there was an “obvious” link between the attack and Friday’s fifth anniversary of Breivik’s attacks in Norway, when he murdered 77 people.
The killer reportedly shouted anti-foreigner slurs during the rampage and yelled “I’m German” at one man who challenged him.
Literature about mass killings was found at his home including a German-language translation of the book Why Kids Kill: Inside the Minds of School Shooters.
Mr De Maiziere said the suspect had researched a 2009 school shooting in Germany as well as the Breivik attack.
“There was material found in the apartment of the suspect that showed a particular interest in shooting sprees,” he said.