Four days later, on the evening of December 19, Anis Amri enters the Fussilet mosque at 6:38 pm, presumably to pray one last time, leaving at 7:07 pm. He went north, along Perleberger Straße, crossed a railway track and then turned left before the canal into Friedrich-Krause-Ufer.

The Polish truck with 25 tons of steel was parked at lamp 16, directly opposite the entrance to the ThyssenKrupp firm. The driver of the truck, Łukasz Urban, was preparing for a night in the truck. Because he arrived at his destination one day too early, he couldn't unload until the next morning.

Amri opened the door of the truck, prompting a fight. Urban's body will later reveal hematomas on the face, chest, and upper arms. Amri pulled out a pistol, an Erma EP 552, caliber 22, with which he shot Łukasz Urban in the left temple. He turned the key in the ignition lock, and released the handbrake. At 19:34 clock the truck started off. The vehicle was easy for a layman to steer, says the freight's owner.

According to the truck's GPS data, Amri drove the truck through the Tiergarten tunnel, past the government quarter, along Potsdamer Platz, past the New National Gallery. He didn't travel faster than 50 km/h, most of the time driving even slower than that. He then reached the Christmas market at the Gedächtniskirche. He drove past Hardenbergstraße, around the roundabout at Ernst-Reuter-Platz and then back again. Shortly after 20:00 he stopped at a red traffic light. As the traffic light turned green, Amri started off. It was 20:02. At around 15 km/h, the truck pushed onto the Christmas market. 15 km/h isn't particularly fast, but on this evening, the market is crowded enough so that he can overrun people and demolish booths. The victims didn't stand a chance.

Amri didn't manage to go any faster. According to an investigator, a string of Christmas trees lights had become wrapped around the axle and blocked the wheel. The truck slowed down, pulled left through the booths and stopped on Budapester Straße. Amri jumped out of the cab and ran to the subway station. In front of a surveillance camera, he flashed the Islamist greeting, the elevated index finger. This was the last trace of Anis Amri in Berlin. Four days later, he was shot dead in Italy.

On that evening, 56 people were injured, some of whom are still in hospital. Twelve died, among them: Łukasz Urban, the Polish truck driver; Fabrizia Di L., a young Italian woman who lived in Berlin; Peter V.; Dalia E.; the couple Anna and Gregoriy B.; and Dorit K. Six of the victims are from Berlin, six are visitors from elsewhere across the world.

The attack's repercusions

On the evening of the attack, the Federal Minister of Interior, Thomas de Maizière, had invited his closest colleagues to a Christmas party in a restaurant in the Nikolaiviertel, when his ministry called him. De Maizière left the bar, and telephoned with the Chancellor. He is suddenly the minister for the state of emergency.

Where does he think the mistakes were made? Three months later, de Maizière is sitting in his office on the sixth floor of the ministry and tries to answer the question. "Well," he says. His sentences never begin with "Well." Then, after a pause, he finds a comparison. He tells of a sex offender whom a reviewer thought to be safe and who had been released from prison. A week later, the man murdered a child. In Amris's case it was similar, says de Maizière. Here, too, the authorities had misjudged Amri's threat and "together made a very severe, incorrect decision."

A few weeks after the deadly attack, de Maizière proposed changes. He wants to integrate the constitutional protection authorities of the 16 federal states into the federal office in Berlin. The BKA is to be given "a right of initiative over other agencies," for example in the case of deportations. "In cases like Amri, we urgently need more commitment and unity among the authorities of the federal government and the federal states," he told ZEIT. De Maizière's proposals are designed to curtail federalism in security policy in order to harmonize procedures.

In Düsseldorf, the North Rhine-Westphalian Minister of Interior, Ralf Jäger (SPD), is standing in front of the edge of a black leather armchair in a large corner office of the ministry. He's visibly annoyed: "This is a devastating attack and shortly thereafter federalism itself is called into question!" With such radical change, the authorities would be occupied with nothing but themselves for years, says Jäger. "We have expertise in this area, we know each other. What will giving jurisdiction to the feds accomplish? "

De Maizière has been much criticized for his proposals: not only by the opposition or civil rights groups. But also by his own colleagues: by Joachim Herrmann, the Bavarian Minister of the Interior, who called the ideas "downright absurd." When it comes to guarding turf, Germany's interior ministers know no parties, only self-interest.

The grand coalition has at least agreed to introduce a new criminal offense. In the case of foreign threats, deportation will be possible in the future if they constitute a "threat to the internal security of Germany." Individuals should also remain in detention, if papers cannot be obtained.

But the real problem hasn't be solved: in the instance of threats, how can fragmented responsibilities be brought together in an overarching, holistic approach. The GTAZ was an invention that fit the situation after September 11, 2001, when the number of terror suspects was in the dozens, not in the hundreds. It's not designed for bulk handling.

On a bitterly cold winter’s day, a crowd walks through the Polish village of Banie to the cemetery. Łukasz Urban, the truck driver, is being buried.

The German federal government sent its deputy ambassador, but suddenly a second German delegation appears with a wreath and sash bearing a Polish and a German flag. One of the men is wearing an Alternative for Germany (AfD) pin. It is Andreas Wild, AfD politician and member of the Berlin Senate. Neither he nor his companions knew Urban, nor did they know his family, but they said that they want "to stand by the Poles," who couldn't help that the Germans elected Angela Merkel. On their wreath it says: "For our heroes."

It is an attempt to gain political benefit from the attack.

At the same time, IS supporters call for further attacks. "Don’t limit yourselves to Christmas markets. There are many simple targets. Every assembly of Kuffar is a target! So jump in and run them over, O lion! "

Somewhere out there is the next Anis Amri, thinking about an attack right now. Germany can only hope that the men and women of the GTAZ, in room A242, get it right next time.

Collaboration: Sebastian Mondial
Translated by Paul Hockenos