In May 1936 he was assigned to the German embassy in Madrid, on the express desire of Heinrich Himmler to investigate the Spanish communists and anarchists. On 18th July, when the coup took place, going from what the fascists intended to be a "Blitzkrieg" to the Spanisch Civil War of three years, Winzer was in Barcelona, where he was watching the German leftists participating in the People's Olympics. After staying there for a few days, Winzer boarded an Italian steamer and returned to Germany. However, when Nazi Germany, which had participated in the war alongside Franco's forces, immediately recognized Franco's legitimacy, Winzer was again sent to Spain with the new ambassador, Wilhelm Faupel, as police "attaché" at the German embassy in the post of "Kriminalkommissar" .