After World War I, Munzinger became a supporter of the growing National Socialist movement and headed the NSDAP/AO chapter in his home country, Latvia.

On the night of April 22–23, 1945, just a few hours before his scheduled release, a special detachment from the Reich Security Main Office murdered him and other prisoners at nearby factory grounds.

After the takeover by the Nazis in the German Empire, Munzinger, who was the head of the Latvian chapter of the NSDAP/AO, was expelled since openly sympathized with Nazism.

During the Second World War, Munzinger was at the Supreme Command of the Wehrmacht (OKW) and worked as an intelligence officer in the Abwehr under Wilhelm Canaris.

After the failure of the assassination attempt of 20 July 1944, Munzinger was arrested by members of the SS in Salzburg and sent to the Lehrterstrasse prison in Berlin.

During the Battle of Berlin, Munzinger was shot together with 14 other Resistance fighters during the night of April 1945 by Gestapo members at a nearby factory premises in the Invalidenstrasse.