On December 9, 1946, an American military tribunal opened criminal proceedings against twenty-three leading German physicians and administrators for their willing participation in war crimes and crimes against humanity. Officially called United States of America v. Karl Brandt et al, the trial was the first of twelve similar proceedings against Nazi doctors held by the United States following World War II.
During the reign of the Third Reich, Nazi physicians planned and enacted the "Euthanasia" Program - the systematic killing of those they deemed "unworthy of life." The victims included the mentally retarded, the institutionalized mentally ill and the physically impaired. Further, during World War II German physicians conducted pseudoscientific medical experiments utilizing thousands of concentration camp prisoners without their consent. Most died or were permanently crippled as a result. Most of the victims were Jews, Poles, Russians, and also Roma (Gypsies).
After almost 140 days of proceedings which included the testimony of 85 witnesses and the submission of almost 1,500 documents, the American judges pronounced their verdict on August 20, 1947 - sixteen of the doctors were found guilty and seven were sentenced to death. They were executed on June 2, 1948.
Sources: U.S. Holocaust Memorial Museum. Trials of War Criminals before the Nuremberg Military Tribunals under Control Council Law No. 10. Nuremberg, October 1946 - April 1949. Washington D.C.: U.S. G.P.O, 1949-1953.