Heinrich Himmler tried to bring the "Zollgrenzschutz" under the control of the "Schultzstaffel" (SS), which was unsuccessful at first. During the war, the units were used in occupied territories outside of Germany. A significant portion of younger officials were recruited to the Wehrmacht, leaving the "Zollgrenzschutz" with older men. After the 20 July 1944 assassination attempt on Hitler, the units were taken out of the control of the Finance Ministry and placed under Amt IV (Gestapo) of the Reich Security Main Office (RSHA).