A show of solidarity in the city of Strasbourg.

We're learning more about Cherif Chekatt, the suspected gunman who authorities say killed several people and wounded about a dozen others at a Christmas market in the French city on Tuesday (December 12) night and is now on the run.

Authorities say that on the morning before the attack they had raided the home of the 29-year-old French national in connection to a homicide investigation, and arrested five other people at that scene.

Chekatt was a known religious extremist who was already considered a potential security risk by authorities.

He had 27 prior convictions across France, Switzerland and Germany on charges including theft and is believed to have been radicalized in prison.

He was even deported from Germany to France at one point, although France says they saw no evidence he was planning an attack.

Now the French-German border is being combed in an effort to find him.

Witnesses say he shouted "Allahu akbar," Arabic for "God is Greatest," during the attack.

A local taxi driver told French media that Chekatt hijacked his car to escape.

He is believed to have been wounded in gunfights with authorities.