On July 24, 2016 in Munich, people mourn the victims of the shooting spree that killed nine people
Munich (Germany) (AFP) - The teenager who shot dead nine people at a Munich shopping mall spent a year planning the rampage but selected his victims at random, officials said Sunday, as police arrested a 16-year-old Afghan friend of the gunman in connection with the attack.
Details are emerging of attacker David Ali Sonboly as a depressed 18-year-old who was obsessed with mass killings and had long struggled with his mental health.
With Germany still steeped in grief and shock, the country was further rattled by news Sunday that a Syrian refugee had killed a woman with a machete in the city of Reutlingen.
Police said that incident did not bear the hallmarks of a "terrorist attack" and was more likely to have been a crime of passion.
However a string of attacks in recent months claimed by the Islamic State group has left Europe on edge.
Investigators have ruled out that the Munich shooter had any link with the jihadists, though he appears to have planned the assault with chilling precision.
Bavarian police chief Robert Heimberger told a press conference Sunday that Sonboly had visited the site and taken photos during a year of preparation.
Chief prosecutor Thomas Steinkraus-Koch added that the gunman had not "deliberately selected" his victims, dismissing speculation that Sonbaly sought to target foreigners.
Police also announced their first arrest in the case, detaining a 16-year-old friend of Sonboly who "could have been aware of the attack".
The Afghan teen reported to police shortly after the killing spree and was questioned about his relationship with the perpetrator, they said in a statement.
But officers then "uncovered contradictions in his statements" and he was now being held for withholding information about a crime.
Most of the dead in Friday's rampage -- who were mainly teenagers -- were foreign nationals. They included a Turk, two Turkish-German dual nationals, a Hungarian, a Kosovan and a Greek, according to police.
Sonboly killed himself after his murderous spree with the 9mm Glock pistol he had bought on the internet.
His attack, which began at a McDonald's branch, also left 35 people injured.
- Bullied -
Steinkraus-Koch said Sonboly had spent two months in a psychiatric unit last year. He suffered anxiety attacks and "social phobias", according to documents found in his bedroom.
Police also found medication, but it was not clear whether he had been taking it. He had continued treatment as an outpatient after his release from hospital.
He also appeared to have been a victim of bullying by other pupils at his school, filing a complaint against three of his tormentors in 2012.
But none of these youngsters were among the shooting spree victims, police stressed.
They added there was no evidence that any of the dead were lured to the McDonald's branch by promises of discounts that Sonboly had sent out from a fake Facebook account, an act Interior Minister Thomas de Maiziere has described as "particularly underhand".
Sonboly was obsessed with Anders Behring Breivik, whose massacre of 77 people in Norway came exactly five years before his own shooting spree.
But police also believe the teenager was influenced by a previous shooting in Winnenden, southwest Germany in 2009, when a 17-year-old shot 15 people in his former school before killing himself.
Born to Iranian parents who came to Germany in the 1990s as asylum-seekers, Sonboly lived in social housing in Munich's well-heeled Maxvorstadt neighbourhood.
- Gun debate -
Hundreds of people on Sunday gathered outside the Munich shopping centre where the attack took place, to pay tribute to the victims. Many were weeping.
With the country on edge after the Munich rampage, it was further rattled by reports that a 21-year-old Syrian asylum-seeker had killed a 45-year-old Polish woman and injured three others with a machete in the southwestern city of Reutlingen.
"At this stage of the enquiry we have nothing to indicate this was a terrorist attack," police said.
"When a man and woman have an argument, we assume that we are dealing with a crime of passion," a local police spokeswoman told German news agency DPA.
The Munich assault has sparked a debate about whether Germany's strict gun laws should be tightened further, and the fact that Sonboly was able to acquire the pistol online will raise questions over how to stop others from doing the same.
Vice Chancellor Sigmar Gabriel, in an interview with the Funke press group, called for a maximum effort to "restrict access to lethal weapons and monitor it closely".
European leaders swiftly voiced solidarity with Germany as the terror alert was launched -- a sign of the jittery mood after a string of jihadist assaults.
The attack came just four days after a 17-year-old asylum seeker went on a rampage with an axe and a knife on a train in Bavaria, injuring five people. He was believed to be a "lone wolf" Afghan or Pakistani inspired by IS.
And it occurred just over a week after a Tunisian used a truck to mow down 84 people after a Bastille Day fireworks display in Nice, the third major attack on French soil in the past 18 months. It too was claimed b IS.