Brazilian police said they arrested a German diplomat Saturday for allegedly killing his husband at their home in an upscale Rio de Janeiro neighborhood, then attempting to cover up the crime. Uwe Herbert Hahn, a German consul, told authorities his husband, Belgian national Walter Henri Maximilien Biot, had taken ill Friday night, collapsing and fatally hitting his head, police said. However, analysis of the body and the couple's apartment in the beach neighborhood of Ipanema found Biot had been severely beaten, they said.