She testified about the crimes committed by Gustav Wagner, including the killing of a sick man who was unable to attend an assembly. She described Gustav Wagner as a "dangerous sadist." An example of Wagner's cruelty, in Felenbaum-Weiss's words:On days that no transports arrived, he would take people from the camp and shoot them himself." Once she witnessed Wagner killing a sick young man, who had not been able to attend roll call: ‘Wagner entered the barracks, called the boy out and shot him in front of all the prisoners."Felenbaum-Weiss also testified against Karl Frenzel, Wagner's deputy. She testified to an example of his cruelty:"One day a special transport arrived at the camp. The people were not wearing regular clothes. Those prisoners wore striped pajamas. They were so skinny and bony, and collapsing from hunger induced weakness. Their heads were shaved and you could not tell the difference between men and women. A rumor was spread in the camp that those people, about 300 hundred of them, arrived from the Majdanek death camp, where the gas chambers ceased to operate. The Germans ordered them to lay down on the ground, and they simply collapsed. Frenzel, an S.S. man, came over and poured a chlorine solution on their heads, as if they were already corpses. The screaming and groaning that came out of their throats were like wounded animal’s howls. It seems that there are no limits to human cruelty." Her testimony was published in a book by Miriam Novitch, published under the title Sobibor - Camp of Death and Revolt in 1979 in Tel Aviv.
