Among them was Amri, a convicted criminal in both Tunisia and Italy with little chance of getting asylum who successfully evaded deportation from Germany even as German authorities rejected his asylum application and deemed the 24-year-old a possible jihadi threat.
He is suspected in the attack that left 12 people dead and 48 injured Monday evening in Berlin. Health officials said 12 of the injured had very serious wounds.
After German media published photos of him and a partial name, federal prosecutors issued a public appeal for information along with the promise of a 100,000-euro ($105,000) reward for his arrest.
Within hours it emerged that the man authorities warned could be “violent and armed” had in fact been known to them for months as someone with ties to Islamic extremists who used at least six different names and three different nationalities.
“People are rightly outraged and anxious that such a person can walk around here, keep changing his identity and the legal system can’t cope with them,” said Rainer Wendt, the head of a union representing German police.
Authorities had initially focused their investigation on a Pakistani man detained shortly after the attack, but released him a day later for lack of evidence. After finding documents belonging to Amri in the cab of the truck, they issued a notice to other European countries early Wednesday seeking his arrest.
According to Ralf Jaeger, the interior minister of North Rhine-Westphalia state, Amri arrived in Germany in July 2015 as the influx of asylum-seekers was nearing its peak.
Although registered in the west of the country, near the Dutch border, Amri had moved around Germany regularly since February, living mostly in Berlin, said Jaeger.
Within months of his arrival, authorities had added Amri to a growing list of potentially violent Islamic extremists, not all of them asylum-seekers.
“Security agencies exchanged information about this person in the joint counter-terrorism center, the last time in November,” said Jaeger.
State prosecutors in Berlin even launched an investigation of Amri on March 14 following a tip from federal security agencies, who warned that he might be planning a break-in to finance the purchase of automatic weapons for use in a possible future attack.
Surveillance showed that Amri did deal drugs in a notorious Berlin park and was involved in a bar brawl, but no evidence was found to substantiate the original warning.