The suspect in the attack on the Christmas market in Berlin remains at large. Police have done raids across the country in search of Annis Amri, whom authorities now consider the prime suspect. Members of his family say he's innocent.

A moment of remembrance — for friends and colleagues. Then -- those who saw the horrors of Monday night — filed out of the Memorial Church and headed back to work determined to carry on.

"The whole thing is very shocking. It’s very sad but life goes on for all of us.”

It is not business as usual here.

A concrete perimeter is now in place to prevent a repeat attack — security has been increased across the city. Because authorities are still searching for the man they believe killed 12 and injured many more: 24-year old Tunisian national Anis Amri.

"We can report today that we have new information that the suspect really is, with high probability, the perpetrator. In the cab, in the driving cabin, fingerprints were found and there is additional evidence that supports this," German Interrior minister Thomas De Maiziere said.

Police special forces carried out raids in three German cities on Thursday — including Berlin. Undated amateur video has emerged, apparently of the man they’re searching for.

Amri had a criminal past — found guilty of crimes in both his home country, and Italy. He was on the radar of intelligence services in Germany months before the attack.

Amri was under surveillance by German authorities since March because of concerns about potential Islamist links. But they stopped in September. And only shared their worries with Germany’s joint counter terrorism center around two months later.

By then he'd disappeared. Though in Tunisia, the suspect’s family say they spoke to him less than two weeks ago.

"If he did something, it will be a dishonor for us all. But I am sure that my brother is innocent. I know why he left home, he left for economic reasons, he left to work, to help the family, he didn't go for such reasons (terrorism). We don't do such things," Suspect's borther Abdelkader Amri said.

Amri’s family has urged him to surrender but so far there is no sign of him.