Martin Gerken was a German communist and one of the highest-ranking Kapos in the Mauthausen-Gusen concentration camp. Between April 1, 1945 and the liberation on May 5 of the same year he served as the camp's elder (German: Lagerältester) of the sub-camp of Gusen.
He started his career within the camp's system as a hut supervisor (German: Blockältester) of one of the huts in Gusen. Although initially known for his crimes against other inmates, in the later parts of World War II he softened his stance. Because of that, he was among the very few Kapos not lynched by other inmates after the escape of the SS guards shortly before the liberation.
References
Martin Gerken Wikipedia(Text) CC BY-SA