After attending secondary school, Weixler studied banking science at the commercial college in Berlin. Christian Social Union in Bavaria protocols show that Weixler belonged to a Christian trade union and was active in Catholic associations. After his military service in the First World War, he joined the Freikorps Epp in 1919, which at that time was involved in the suppression of the Munich Soviet Republic. From 1922 to 1924 he worked in Berlin at the Creditbank for industry and agriculture. Then he was until 1926 as director of the Reichsbundbank AG and from 1926 to 1930 as co-owner of the construction partnerships Weixler & Coactive in Berlin. From 1930 he headed the branch of the Prussian State Pfandbrief Institution in Munich.
In 1933 Weixler became a member of the NSDAP and the SS. In 1934 he was excluded there for political reasons and participated in resistance groups. In 1934 he was arrested. Special court proceedings against him were terminated in the course of an amnesty. In 1937 he also lost his position at the bank for political reasons and worked as a freelance photographer and author from 1937 to 1939. In 1939 he came to the German Wehrmacht as a war correspondent and took part in the Balkan campaign in 1941 with the airborne battle over Crete. In addition to his normal camera, he also worked with a stereoscopic camera and sometimes used rare color films at that time. War rapporteurs were given the task of providing the National Socialist-led Ministry of Propaganda with photos that only painted a positive, as heroic picture of the German view of war as possible. Franz-Peter Weixler didn't necessarily stick to it. On June 2, 1941, he used a series of photos to document the shooting of 23 unarmed Greek civilians in the small Cretan village of Kondomari by German soldiers, which they named in retaliation for alleged Greek atrocities by German paratroopers. Taking such photos and, moreover, showing them uncensored to unauthorized persons was seen as a disintegration of the armed forces and was to be punished with death under martial law at the time. Weixler was denounced, arrested and in March 1944 on charges of treason and continued military morale to the Munich prison Neudeck spent. After the relevant files were burned during the war, the process was delayed until the end of the war and the photographer avoided being convicted.
Later life
In November 1945, Franz-Peter Weixler gave a written testimony and his documentary photos of the executions of Kondomari to the Nuremberg War Crimes Trial Court. In his home town of Krailling, he was one of the founding members of the local Union CSU. He died on April 23, 1971 in Bad Reichenhall. The German Historical Museum in Berlin holds around a thousand photos of Weixler, which show the entire spectrum of his work.