German security and intelligence services knew about the potential danger posed by Anis Amri prior to his December truck attack in Berlin, but failed to identify the threat even after conducting seven meetings on the would-be terrorist.

MOSCOW (Sputnik) — According to the information, disclosed by security officials at a regional parliamentary hearing on Thursday, German security and intelligence services failed to detain the terrorist, despite extensive surveillance, because the services thought they did not have enough evidence for a court trial, the Wall Street Journal reported Thursday.

"Nobody understands how a known extremist was able to walk around freely in this country … what authorities knew was hearsay. That is not enough to arrest someone. You need to convince a judge," Gregor Golland, a German regional lawmaker from the Christian Democratic Union, said prior to the questioning of security officials on Thursday, as quoted by the newspaper.

Among the extensive evidence that the German services had were the fact of Amri using 14 different identities, reports of radical Islamism by his roommate, evidence of attack planning, tips from Tunisian and Moroccan security agencies that Amri supported Daesh (outlawed in Russia and Germany).

The German security services met seven times to discuss Amri throughout the year of 2016.

Twenty-four-year-old Tunisian Anis Amri rammed a truck into a busy Christmas market in central Berlin in December, killing 12 people. Amri fled to Italy where he was shot dead by Milan police officers during a routine check. It emerged later that the attacker had pledged allegiance to the Daesh terror group.