A suspect is still at large after terrorists used a semi-truck to attack citizens at a Berlin Christmas market:

There are new reports saying that the man had been in custody previously — multiple times — and released:

The Daily Mail reports:

A Tunisian asylum seeker suspected of carrying out the Berlin massacre was arrested three times this year amid fears he was planning a terror plot – but police let him go.

Despite being an ISIS supporter known to have received weapons training, German authorities allowed Anis Amri to slip through their clutches time after time and have now offered a 100,000 euro reward for information leading to his capture.
Police today revealed they have launched a Europe-wide hunt for the refugee, who came to Germany last year. His paperwork was found in the footwell of a lorry used to murder 12 people on Monday night.

The Daily mail also added this aspect to the story: