BERLIN — Walter Luebcke, a politician from Chancellor Angela Merkel’s party, was found dead from a gunshot wound to the head outside his home in Hesse state, German authorities confirmed Monday. Authorities launched a homicide investigation but have not identified suspects or a possible motive. Luebcke, who was in charge of the Kassel area regional administration, was found outside his home early Sunday morning by a relative and attempts to reanimate him were unsuccessful, said Hesse prosecutor Horst Streiff.