The prime suspect sought in the deadly attack on a Berlin Christmas market - a 24-year old Tunisian migrant - was the subject of a terrorism probe in Germany earlier this year and was not deported even though his asylum bid was rejected, a senior official said Wednesday.
The suspect - who went by numerous aliases but was identified by German authorities as Anis Amri - became the subject of a national manhunt after investigators discovered a wallet with his identity documents in the truck used in Monday's attack that left 12 dead, two law enforcement officials told The Washington Post.
Meanwhile, a clearer portrait took shape of the suspect, including accusations that he had contact with a prominent Islamic State recruiter in Germany.
German authorities issued a 100,000 euro ($105,000) reward for information leading to his capture, warning citizens not to approach the 5-foot-8, 165-pound Amri, whom they described as "violent and armed."
His record, however, further deepened the political fallout from Monday's bloodshed - pointing to flaws in the German deportation system and putting a harsh light on Chancellor Angela Merkel's humanitarian bid to open the nation's doors to nearly 1 million asylum seekers last year.
Although the vast majority of those who flooded into Europe were on the move to escape war and unrest, dozens of terrorism suspects have slipped into Germany and neighbouring nations posing as migrants. Amri, officials said, was not part of the surge of migrants who entered Europe via the onetime main route from Turkey and Greece - a path that has been now largely cut off.
Rather, he came to Germany last year via Italy, where he apparently had entered as early as 2012. He applied for German asylum but was rejected in June and later faced deportation.
Amri was the subject of a terrorism probe on suspicion of "preparing a serious act of violent subversion," and he had known links to Islamist extremists, authorities said.
Why a failed asylum-seeker with such links and no passport was walking German streets is "the question 82 million Germans probably want an answer to," said Rainer Wendt, Chairman of the German Police Union.
He added: "How many more ticking time bombs are roaming around here? . . . We saw how much damage one person can do with a truck."
The dragnet for the suspect appeared to initially focus on the German state of North Rhine-Westphalia as well as Berlin, both places where the Tunisian suspect once lived. Police units were due to stage raids but remained mysteriously on hold.
The interior minister in North Rhine-Westphalia, Ralf Jäger, said the Tunisian man had bounced around Germany since arriving in July 2015, living in the southern city of Freiburg and later in Berlin.
Although authorities have sought to accelerate the deportation of rejected asylum-seekers this year, there is still a backlog in Germany of tens of thousands, many of whom are able to resist because their countries of origin refuse to take them back. Amri, Jäger said, was one of them.
Amri had not been deported because - like many asylum seekers in Germany - he did not have a passport. The Tunisian government, Jäger explained, initially denied that he was their national and delayed issuing his passport. Pending his deportation, Amri had received a "toleration" status from the government.
Amri's new Tunisian passport, Jäger said, finally arrived Wednesday.
"I don't want to comment further on that circumstance," said a visibly angered Jäger.
Importantly, authorities knew that Amri had "interacted" with Abu Walaa, a 32-year-old of Iraqi descent arrested in November on charges of recruiting and sending fighters from Germany to the Islamic State. Key evidence in Walaa's case came from an Islamic State defector who had returned to Germany and accused Walaa of helping to recruit him and arrange his travel to Syria.
"Anis Amri was engaging with extremist salafist circles in Germany," the official said.
According to Karen Müller, spokeswoman of the Berlin prosecutor, Amri had also been under police surveillance for several months until September this year, because he was suspected of planning a burglary in Berlin to finance the purchase of weapons. The suspicion wasn't confirmed. He was, she said, only found to be a small-time drug dealer.
The leaking of the suspect's name and photograph in the press, authorities said, may have upset attempts to find him. Germany's interior minister, Thomas de Maizière, would tell reporters in Berlin only that Germany had registered "a suspect" as wanted European databases. He refused to give further details.
The two German law enforcement officials, who spoke on the condition of anonymity to discuss a sensitive case, said investigators discovered the man's documents in the cabin of the truck that barrelled into the market.
It remained unclear whether authorities believe the Tunisian man drove the truck, but police nevertheless made tracking him a priority.
Revelation of the asylum seeker's background sparked outrage among conservative politicians and seemed set to damage Merkel, who is running for re election next year.
"There is a connection between the refugee crisis and the heightened terror threat in Germany," said Stefan Mayer, parliamentary spokesman for the Christian Social Union party on domestic affairs told reporters. "This can also be seen in the case of this Tunisian."
President-elect Donald Trump on Wednesday appeared to stand by his plans to establish a registry for Muslims and temporarily ban Muslim immigrants from the United States.
Speaking outside of his Mar-a-Lago resort in Florida, Trump did not walk back the proposals after he was asked by a reporter whether he was rethinking or re evaluating them in the wake of a fresh terrorist attack in Berlin.
"You know my plans," Trump said.
He went on to add that the attack on a Berlin Christmas market, which was claimed by the Islamic State, had vindicated him.
"All along, I've been proven to be right. One hundred percent correct," Trump said. "What's happening is disgraceful."
Germany's Bild newspaper said Amri had several aliases and was apparently born in the southern Tunisian desert town of Tataouine in 1992.
Witnesses described one man fleeing the scene after the truck - packed with a cargo of steel - roared into revellers at a traditional Christmas market. One suspect, a Pakistani asylum-seeker, was arrested Monday night, but authorities later released him because of a lack of evidence.
The new information emerged as German investigators raced for clues in the hunt for Amri and other possible suspects in the deadly assault. They pored over forensic evidence and GPS data as they sought to retrace the steps of the runaway attacker. They were re-questioning witnesses and analysing DNA traces found in the truck, as well as on the body of a dead Polish man in the passenger seat.
The Pole worked for a trucking company and was delivering a payload of steel to Berlin. Investigators are going on the assumption that he was taken hostage by the assailant - and may even have died a hero. Jörg Radek, deputy chairman of the German Trade Union of the Police, said evidence suggested that "a fight took place in the driver's cabin." As it careened toward the crowded market, the truck was not driving straight, but "in a zigzag line," he noted.
The Islamic State on Tuesday claimed responsibility for inspiring the unknown attacker - a claim as yet unproven and possibly just opportunistic. But it fuelled some politicians to quickly point the finger at Merkel's refugee policy, even as others pushed back, calling the accusations a politicising of tragedy that had no place in progressive Germany.
There were also growing calls for the deployment of more police on the streets with military-style weapons - an unusual move in pacifist Germany. At the normally quaint and picturesque Christmas markets in at least three German cities - Mainz, Magdeburg and Dresden - concrete barriers were quickly erected to add security. In Magdeburg, police officers armed with automatic weapons were guarding the entrance.
Yet others argued that living a free society was perhaps more important and that Germans were willing to accept a certain measure of risk to preserve that openness.
"If we want to maintain the freedom of our society, we simply have to live with the risk contained in this decision," Die Tageszeitung said in a Wednesday editorial.