Belle Mayer trained as a lawyer and worked for the General Counsel of the US Treasury, Foreign Funds Control Bureau. This bureau worked to enforce the Trading With the Enemy Act passed by Congress. In this capacity, Mayer became familiar with the German I. G. Farben chemical company, a large conglomerate that used slave labor during World War II. In 1945, Mayer was sent as a Department of Treasury representative to the postwar London Conference. She was present as representatives from the Allied nations outlined the principles of law for the prosecution and trial of Europe's major war criminals. Mayer reported to this commission as it prepared for upcoming war crimes trials. She was then among the attorneys (including her future husband William Zeck) who prepared the indictment against the I. G. Farben company at the Nuremberg trials.
None of the economics people were sentenced to death or anywhere near it, and it was because if these leaders of the economic life of the country had got such light sentences, then I couldn't see their going after these men who looked like businessmen, talked like businessmen, and were really murderers.