BERLIN (AP) — German authorities say they have arrested two men in connection with the killing of a politician from Chancellor Angela Merkel's party, one of whom is accused of selling the weapon allegedly used by the main suspect.

Walter Luebcke, who led the Kassel regional administration in central Germany, was shot fatally at his home on June 2. A 45-year-old German man with a string of convictions for violent anti-migrant crime, Stephan Ernst, was later arrested as the alleged killer.

Officials said on Wednesday that Ernst has admitted to carrying out the killing and says he acted alone. Federal prosecutors said Thursday that they have arrested two other Germans, one of whom is accused of selling him the weapon in 2016 and the other of putting Ernst in contact with the seller.