Suspect had been investigated over earlier terror plot
Anis Amri, a 24-year-old rejected asylum-seeker from Tunisia, became the most wanted man in Europe yesterday.
Germany offered a €100,000 reward for information leading to the capture of the man who is now the prime suspect in the Berlin terror attack.
But as details of the investigation emerged, it quickly became clear that Amri is not the undetected jihadi hiding among a million migrants Germany has long feared. He was well-known to police, and had long been identified as a potential terrorist.
He was supposed to be under surveillance, but had somehow managed to give his watchers the slip just weeks ago.
Amri was investigated earlier this year by German police over a suspected attempt to buy automatic weapons for an unconnected terror plot.
He was a known criminal who fled his native Tunisia to escape imprisonment, and spent time in Italy.
But he failed to stay out of trouble in Italy. He was jailed for some time, reportedly over an arson attack at a school.
After his release, he travelled on to Germany, arriving in July 2015 as the European migrant crisis was developing, but a month before Angela Merkel had opened the country's borders to asylum-seekers.
He entered Germany at Freiburg, near the border with Switzerland and France, and lived for some time in the southern state of Baden-Württemberg, before moving north to the state of North Rhine-Westphalia.
According to a European arrest warrant issued by Germany, Amri used at least six different aliases and three different nationalities, claiming at times to be Egyptian or Lebanese.