German anti-terrorism experts believed Berlin truck attack suspect Anis Amri was unlikely to commit an assault, even though he was a known Islamist who had volunteered for a suicide attack, a report said Thursday.
Officials also knew Amri was tightly linked to Germany's radical Islamist network and had looked up instructions online to build pipe bombs, the Sueddeutsche Zeitung daily reported.
The latest version of their file on Amri, which included information on his eight different identities, was updated on December 14 -- just five days before he rammed a truck into a crowded Christmas market in Berlin.
Duesseldorf police deemed him a Salafist and radical fundamentalist, while Dortmund police had rated him a sympathiser of the Islamic State group.
Amri had been a regular guest at a religious school in a Dortmund apartment run by a notorious radical known as Boban S. that was believed to be a recruitment ground for jihadists.
Nevertheless, on an eight-point scale assessing an individual's potential danger, with "one" the highest threat, counter-terrorism experts rated him a "five" -- meaning they considered an attack possible but unlikely.
Shortly after the Christmas market rampage, authorities admitted that counter-terrorism services had been watching Amri, suspecting he may have been plotting an attack.
But surveillance was dropped in September, as police thought he was primarily as a small-time drug dealer.
Chancellor Angela Merkel ordered a sweeping review of the security apparatus after the attack, so that any necessary reforms could be agreed and implemented quickly.