In 1944, he became part of Adolf Diekmann's brigade, being under the direct command of Otto Erich Kahn. He then took part in the June 1944 Oradour-sur-Glane massacre by leading the group which led the men of the village into a barn and commanding the fire. During his 1983 trial, he testified to having personally shot roughly fifteen times into the crowd. He also confirmed that the massacre of 642 civilians (the whole village, including more than 200 children) had no military objective.