BERLIN - The German government, under fire for failing to prevent a deadly car-ramming attack on a Christmas market, argued that the tragedy would have been hard to prevent and said that the suspect appeared to be mentally disturbed.
Interior Minister Nancy Faeser along with security and intelligence chiefs faced questioning by a parliamentary committee about the attack that killed five people and wounded more than 200, and on whether there had been missed clues and security lapses.
Faeser said no motive had yet been established for the December 20 attack in the eastern city of Magdeburg, where a Saudi man was arrested, but that "there are striking signs of a pathological psyche".
She added that lessons must be learnt on how to track potential attackers who don't fit conventional threat categories and who "are psychologically disturbed and... driven by confused conspiracy theories".
The minister argued that "such attackers do not fit any threat profile" -- such as far-right extremist or Islamist -- and warned that German security services will need "other indicators and action plans" to deal with them in future.
Police arrested Saudi psychiatrist Taleb al-Abdulmohsen after the assault that used a motor vehicle as a weapon, a method previously used in jihadist attacks including in Berlin and in the French city of Nice in 2016.
Abdulmohsen, by contrast, has in the past voiced strongly anti-Islam views and sympathies with the far right in his social media posts, as well as anger at Germany for allowing in too many Muslim war refugees and other asylum-seekers.
Faeser said there were "tens of thousands of tweets" Abdulmohsen had sent over the years that were yet to be fully examined.
"That explains why not everything is on the table yet... who knew about which clues and what was passed on when must be carefully clarified," she said.
Abdulmohsen is the only suspect in the attack in which a rented BMW sport utility vehicle ploughed through the crowd of revellers at high speed, leaving a bloody trail of carnage.
According to media reports citing unnamed German security sources, he has in the past been treated for mental illness and tested positive for drug use on the night of his arrest.
Abdulmohsen has been remanded in custody on five counts of murder and 205 counts of attempted murder, prosecutors said, but so far not on terrorism-related charges.
Chancellor Olaf Scholz, who faces a general election in February, vowed to news portal T-online on Friday to "examine very carefully whether there were any failings on the part of the authorities" and whether any clues were missed in the run-up to the attack.
German media investigations of Abdulmohsen's past and his social media postings have found expressions of anger and frustration, and threats of violence against German citizens and politicians.
Saudi Arabia said it had repeatedly warned Germany about, and demanded the extradition of, Abdulmohsen, who came to Germany in 2006 and was granted refugee status 10 years later.
Abdulmohsen also had a history of brushes with the law and court appearances in Germany, media have reported, including for threats of violence.