BERLIN (AP) — German investigators on Thursday carried out raids on dozens of people suspected of posting hate messages about a regional politician from Chancellor Angela Merkel’s party who was killed last year.

Walter Luebcke, who led the regional administration in the central Kassel region, was shot on his porch on June 1, 2019, and died later that night. His killing sparked widespread outrage in Germany and warnings about the growing danger of violent far-right extremism.

A man with previous convictions for a string of violent anti-migrant crimes has been charged with murder in the case. Prosecutors say that he attended an October 2015 town hall event where Luebcke defended the German government’s decision to allow hundreds of thousands of refugees into the country. A video of Luebcke’s remarks was widely shared in far-right circles, drawing numerous threats.

Frankfurt prosecutors said that authorities in 12 of Germany’s 16 states conducted searches and questioning of 40 people suspected of posting “criminally relevant comments” about Luebcke, largely on various social media networks. The action was the result of an investigation launched in September.

They are being investigated on suspicion of offenses including public incitement to commit crimes, endorsing crimes and disparaging the memory of the dead.

Prosecutors in Bavaria, where seven of the suspects live, said the comments were posted both before and after Luebcke’s death.