The chemist Arthur Ketzer ran the Berlin-based company Dr. Armin Bauer & Co GmbH. Ketzer was a determined opponent of the Nazi regime from the outset. In the time before the war, he helped several families to emigrate from Germany. After the deportations of Jews began, he took people at risk into his home or provided material support. Walter and Leonie Frankenstein and their two sons hid in his apartment. He employed Gertrud and Werner Scharff, who were living underground, under false identities at his company. Via the Scharffs, Ketzer came into contact with the Community for Peace and Reconstruction. This resistance group helped persecuted people and sent chain letters calling on the general public to resist the war and the Nazi crimes.
The Gestapo began investigating the group in the fall of 1944. Arthur Ketzer was arrested and put into a “labor education camp” for “aiding Jews.” By means of bribery, he arranged for furlough in February 1945 and used his temporary release to escape.
In 2007 the Israeli Holocaust memorial center Yad Vashem honored Ketzer as Righteous Among the Nations, on the initiative of Walter and Leonie Frankenstein.