William Denson graduated from the US Military Academy at West Point in 1934 and attended Harvard Law School. He returned to West Point to teach law from 1942 until 1945. In January 1945, Denson accepted the position of Judge Advocate General (JAG) in Europe and was assigned to US Third Army headquarters in Germany. He took part in more than 90 trials against Germans who had committed atrocities against downed American pilots. In August 1945, Denson became chief prosecutor for the US government at the Dachau concentration camp war crimes trial. He was also asked to serve as chief prosecutor for a series of other concentration camp trials, including Mauthausen, Flossenbürg, and Buchenwald. These trials came to an end in early 1947, and Denson returned to the United States.
I don't think there's much doubt about the fact that anybody that came in contact with them, with the evidence, of course, they saw it. It was a credible matter to them. But from the secondhand on, it was an incredible matter. And the biggest problem that I had after I was designated to prosecute these case, the biggest problem that I had was believing or getting testimony that could be believed. Because of its nature. Not that it wasn't true. It was true. But the events that were depicted were so horrible, were so sadistic, were so monstrous, that they were incredible. That's the only way to describe it. And I was a skeptic. I didn't believe it at that time. I didn't start believing it until I really started digging in too with the concept and with the authority that I was going to prosecute the Dachau concentration camp case. At that time when I started talking to witnesses, and I heard events there that were so out of line, that they were incredible. I could give you an event that perhaps might depict it. In all of these camps there was place in the camp called the arrest bunker. And in the arrest bunker there was some cells which were called the standing cells. They were instruments of torture in reality because they were so small and so constructed that it was almost impossible for -- almost impossible -- it was impossible for a prisoner who had been committed to one of these cells to either lie down or to sit. He had to stand in order to be within the confines of the cell. And these SS men who were in charge of the arrest bunker would put prisoners in there for punishment. They received no food, no water, and no chance to sit down or lie down, or change their position for three to five days. And sometimes longer if they lived that long.