Before joining the US Army, Zeck—a lawyer—worked for the Board of Economic Warfare. In 1946, he was hired to work on preparations for the Nuremberg trials. In his search for documents pertaining to the I. G. Farben company's involvement in the war, Zeck also met attorney Belle Mayer, his future wife. Both Zeck and Mayer were involved in preparing the indictment in the I. G. Farben trial held at Nuremberg.
Much of the stuff, the documentation part of it, didn't have any fireworks, you see, because under the rules established, every document had to be translated into four languages and document books, with respect to each defendant, had to be delivered in advance to the defendant's counsel. And so it was a very slow and quite tedious process. But the reason really, the basis for the convictions was very much more the documentation than the interrogation of the witnesses. The witnesses all said "Superior orders, Hitler ordered it, we had to do it."