The Tunisian man who plowed a truck through a crowded Christmas market in Berlin last month was identified as a threat by German authorities in February of last year.
German investigators classified Anis Amri as a danger after receiving evidence in early February 2016 that he had been in contact with suspected Islamic State jihadists and had offered to serve as a suicide bomber on behalf of the terrorist group, the Sueddeutsche Zeitung reported, according to Reuters. Authorities ultimately decided Amri was unlikely to carry out an attack.
Amri was shot dead by police in Milan four days after he drove a truck through the Berlin Christmas market, killing 12 people.
ISIS claimed responsibility for the attack and called Amri a "soldier" of the militant organization, mirroring statements released after previous lone wolf attacks, including the Nice, France vehicle massacre that killed 86 people in July.
Amri, 24, traveled to Italy in 2012 before arriving in Germany in 2015 where his application for asylum was later rejected. Authorities were unable to deport him because Tunisia initially denied he was a citizen. Passport documentation from Tunisian officials arrived in Germany two days after the attack.
German authorities detained Amri in August with fake Italian identity documents.
Berlin remains on high alert for terrorism following the attack.