Shortly after the Berlin truck terrorism suspect Anis Amri was killed in a shoot out with Milan police, railway tickets found on Amri's body showed he had traveled from Chambery in south-eastern France to Turin and then on to Milan, according to Italy's Ansa. Which is strange because while he kept ticket stubs, he had virtually nothing else on him: Milan police said Amri was carrying few personal belongings, had no cell phone and no other arms apart from a small knife in his backpack. He had several hundred euros but no documents. "He was a ghost, he didn't leave a trace," said Milan police chief Antonio De Iesu.

In any case, the newly revealed details of his trip mean that Europe's most wanted man traveled unhindered through at least three countries - Germany, France and Italy - before being gunned down in northern Italy.

He travelled out of Germany and all the way to Chambery railway station in the French Alps. He then took a three-hour direct train to Turin, and then on to Milan's Central Station where he arrived at 1am, and then on to the suburban Sesto San Giovanni station where he was killed by police at 3am.

It is not known how he got to France from Germany but if it was by train the quickest route would be from Berlin to Frankfurt, then on to Lyon. According to the Mail, at least one report suggests Amri may have gone to Paris before heading towards the Alps and Italy over the past five days. German Police will search for any abandoned cars in case he left Germany by road before switching to the railways.

Today Amri, 24, had just stepped off a train from France when he was stopped by a routine police patrol in the suburb of Sesto San Giovanni in Milan. The Tunisian asylum seeker screamed 'Allahu Akbar' and pulled a pistol from his bag and shot policeman Christian Movio in the shoulder. A firefight ensued with Amri cowering behind a car as he tried to flee, but Luca Scatà, a trainee police officer who had only been in the job a few months, gave chase before shooting him dead in the street.

As reported previously, Amri had strong links to Italy because it was the first European country he claimed asylum in. In 2011 he dodged prison in his native Tunisia after fleeing following a violent robbery. He was jailed for five years in absentia. He arrived in Italy in 2011, arriving on the small island of Lampedusa amongst thousands of people fleeing the Arab Spring uprisings.

After his release Italy failed to deport him twice because Tunisia refused to take him back and he fled Italy via the Alps for Germany, meaning he probably went via Milan. He looks to have followed a near identical route back - yet German police appear to have completely misjudged the distance Amri was able to travel after the attack on Monday night.

As a result, attention has shifted to tactical blunders by the German police, as Amri slipped through their fingers.

As the Daily Mail adds, "blundering German police today said they believed the Tunisian asylum seeker was still in or around Berlin just before he was shot dead almost 1,000 miles away in Milan. Officers have been raiding addresses across Germany in the hunt for Amri, but after arresting the wrong man the ISIS terrorist was able to flee the country." Adding insult to German police injury, this morning, before his death was announced, a senior police source told tabloid Bild: ‘We believe he is either in Berlin or in North Rhine-Westphalia’.

As we speculated yesterday, Amri's escape from Germany is pouring on the embarrassment for Chancellor Angela Merkel, who yesterday said she believed they would arrest him 'soon'. Not surprisingly, according to an Insa Poll conducted December 21-23 and published in Germany's Bild, Merkel's CDU declined again in the latest polls.

German security services have already been heavily criticised for the way they have handed the investigation. First police arrested the wrong man in the aftermath of the attack - a Pakistani asylum seeker who accidentally jumped a red light near Breitscheidplatz. Innocent man Naveed Baluch, 23, was flown across the country to Karlsruhe to be questioned, but was released 18 hours later after he was found to have no blood on his clothes and no injuries.

In that time Amri was allegedly caught on a security camera as he stood outside a mosque he was believed to have frequented in Berlin's Moabit neighbourhood. The next blunder came when German police took a day to find his wallet under the truck's front seat and they only managed to confirm his fingerprints were on the wheel yesterday.

The country's security was placed under fresh scrutiny following revelations covert surveillance had been ditched against the 24-year-old after more than six months due to police finding nothing to substantiate an initial tip-off. Yesterday it was revealed that wire taps grabbed two months ago showed Amri had told a hate preacher that he was willing to blow himself up - and had also inquired about buying automatic weapons from a police informant. But German officers still did not believe they had enough evidence to arrest him, according to Spiegel.

A near-total ban on CCTV in public spaces also meant that German police and security services had no live footage of the Christmas market massacre or the killer driver fleeing the scene.

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But while Merkel and the German response will be probed and questioned for weeks to come, another target of Eurosceptics has emerged: Europe's passport-free travel, the Schengen Area, which allowed Amri to cross two international borders without as much as a question.

As a result, leading Eurosceptics have blamed the Schengen agreement, which allows passport-free travel between many European Union states, for Anis Amri's easy journey across Europe.

Marine Le Pen, who leads France's far-right National Front party, said: "This escapade in at least two or three countries is symptomatic of the total security catastrophe that is the Schengen agreement."

Former UKIP leader Nigel Farage said on Twitter: "If the man shot in Milan is the Berlin killer, then the Schengen Area is proven to be a risk to public safety. It must go."

If the man shot in Milan is the Berlin killer, then the Schengen Area is proven to be a risk to public safety. It must go. — Nigel Farage (@Nigel_Farage) December 23, 2016

While it is unknown if this particular incident will be sufficient to end the Schengen Area customs-union, should the Amri attack be followed by one or more similar terrorist attacks in the coming weeks, it may just be the final straw that forces Europe to crackdown on passport-free travel. It will likely also have significant consequences on the 2017 German elections, where despite the recent snafus, Merkel's CDU is still seen as a big favorite to win.