On Friday morning police officers in Milan stopped Anis Amri as he was walking through Sesto San Giovanni in the north of the city.
Instead of showing his ID as requested, Amri pulled out a weapon and shot at the officers, wounding one. The Italian cops returned fire, fatally wounded the fugitive Tunisian.
Four days after Germany's first major Islamist terror attack, the prime suspect is dead.
And after Amri's ID was found in the cabin of the truck and his fingerprints were found on the driver's door prosecutors have little doubt that he was the man who murdered 12 people at Breitscheidplatz on Monday.
But his death will be followed by a long period of soul searching in Germany.
Questions are already being asked as to who was to blame for the terror attack and how more attacks can be prevented.
Is this all Merkel's fault?
Within hours of the attack, before police had identified a suspect, far-right politicians caused outrage by describing the victims in Breitscheidplatz as “Merkel's dead.”
According to AfD head Frauke Petry, "the milieu in which such acts can flourish has been negligently and systematically imported over the past year and a half."
The far-right have long claimed that opening up Germany's borders to undocumented migrants from Muslim countries was a recipe for trouble.
Since the beginning of 2015, 1.2 million people have arrived in the country seeking asylum.
Amri was one of these people. He left Italy for Germany and made an asylum application in North Rhine Westphalia in April 2016.
While even the leadership of the AfD have rejected the claim Merkel is directly accountable for the deaths, influential figures in her own CDU party are also saying the migrant influx contributed to the tragedy.
Wolfgang Bosbach, the CDU's domestic affairs expert, told broadcaster n-tv on Friday that the only way future attacks can be prevented is to stop people like Amri entering the country in the first place.
Bosbach pointed out that Germany wanted to deport Amri months ago but could not do so as they were not able to prove he was a Tunisian citizen. He didn't have official documentation and Tunisia denied he was Tunisian, meaning he had to be set free.
The CDU expert said that Germany should not allow anyone into the country before they provide official documents proving who they are.
In the election year 2017 Merkel's critics on the right are almost certain to use the attack to claim that she has neglected the security of her own citizens.
The public mood had already turned against Merkel's refugee policies. A poll on Friday showed just how worried may people are - one in four now avoid big crowds of people, the YouGov poll showed.
Merkel will be more vulnerable than ever as she makes the case for re-election in the autumn.
Nevertheless supporters of Merkel's refugee policy have come out in her defence. The Süddeutsche Zeitung wrote this week that the attack was the “price of showing humanity.”
Could the police have stopped him?
There is almost certain to be a federal enquiry into the workings of Germany's police services, after a series of potentially scandalous revelations since the attack.
The interior minister of North Rhine-Westphalia (NRW), Ralf Jäger, has confirmed that there was a previous terror probe into Amri in his state.
But the Tunisian moved to Berlin in February and a lack of cooperation between investigators in the two states potentially contributed to his danger being underestimated.
Meanwhile Spiegel reported on Thursday that investigators had heard Amri offering to be a suicide bomber to radical preachers months ago.
Despite much evidence that he was dangerous, Amri was able to disappear in November.
Police lost track of him until his deadly crime. But new CCTV evidence suggests he appeared twice in December at a radical Berlin mosque which is under police surveillance. The mosque in the Moabit neighbourhood lies across the street from a police station.
Questions are also being asked about how Amri was able to escape after his attack.
CCTV footage hows that he again appeared at the mosque eight hours after the truck attack at Breitscheidplatz. This was however before police had found his ID in the truck.
An official investigation could lead to an overhaul of how police services in different states work with one another. It could also lead to heads rolling in NRW, where authorities have already been under investigation for their handling of sexual assaults last New Year.
Do the police have enough power?
Senior police officials have reacted angrily to the suggestion that they are at fault for the attack.
Rainer Wendt, head of the German Police Union, told the Rheinische Post: "I find it shameful to talk of a failure on the part of the police in the case of Anis Amri.”
For the police , the problem is restrictive laws they claim tie their hands.
They have called for an extension of the use of CCTV in public spaces and for powers to detain suspects for longer periods of time.
They also say they need much larger resources to be able to monitor the comings and goings of potential terrorists.
The interior ministry says that 330 people are considered dangerous in Germany.
Police would need 40 officers for each one of them if they want to monitor them around the clock, Sebastian Fiedler from the federation of federal investigators told ARD.
In NRW that would mean a thrid of their total police force.
After smaller terror attacks in July the government has already brought in extensions to the state's power to use CCTV in public. After Breitscheidplatz there is certain to be another review of police powers.
But critics point out that the German constitution, with its high levels of protection of privacy, make radical changes to the law impossible.
Cooperation between EU countries
Amri had been sentenced to prison in Italy for four years after he tried to set fire to a school in Catania.
In 2015 he was detained and Italy attempted to deport him back to Tunisia, but the attempt failed because he didn't have official documentation.
So Italian authorities released him and told him to leave the country. He was then able to travel to Germany and make an asylum request.
While Germany will no doubt be thankful to the Italians that they caught Amri on Friday, there will be anger that he was able to travel on to Germany despite his record. An urgent issue in need of clarity will be how much information Italian police gave their German counterparts when Amri left the country.
This follows the case of an Afghan refugee who was imprisoned in Greece for attempted murder before travelling into Germany where he is suspected of raping and murdering a student in Freiburg.
Greece is accused of not issuing a notification to its Schengen partners, meaning Germany didn't recognize the threat..
With the Schengen Agreement meaning people can travel between European countries without showing official documents, both these cases are already raising questions about how EU countries can work together to track known criminals.