After attending a humanistic Gymnasium in Rostock, Rademacher studied law at the Universities of Munich and Rostock, passing his second Staatspriifung (State examination) in April 1932.
After the studiers he became an assistant judge. A member of the NSDAP from March 1933 (he joined the SA in the summer of 1932 but left two years later), Rademacher entered the Foreign Office as Legation Secretary at the end of 1937. In 1938 he was assigned as chargé d'affaires to the German embassy in Montevideo, Uruguay, a post he held until in May 1940 he returned to Germany, taking over the Jewish Referai in Abteilung Deutschland under Martin Luther. A career-minded bureaucrat who brandished his pseudo-scientific anti-semitism very conspicuously, Rademacher was closely involved in the planning for the ‘Final Solution' during the three years he served under Luther.
In 1940 he drew up the so-called Madagascar Plan, which envisaged a massive expulsion of European Jewry to the French colony, but this project was dropped once the war w ith the USSR created the possibility of sending Jews to the East and implementing a ‘Final Solution’ in Europe itself. Rademacher believed in the necessity of such a ‘solution', though initially he had not envisaged systematic extermination. In constant contact with Adolf Eichmann's office, acting sometimes as a messenger boy for his liquidation arrangements and sometimes as an intermediary between him and the Foreign Office, Rademacher's name appears on countless documents concerning the deportation of European Jews to death camps in Poland. He supervised the murder in cold blood of Jews in Belgrade in October 1941 by Nazi occupation forces, for which he was later sentenced after the war. He was also involved in the deportation of Belgian, Dutch and French Jews. After April 1943, following the fall of Luther, Rademacher's own career in the Foreign Office was in a shambles and he enlisted as a naval officer until the end of the war.
Arrested by the Americans in September 1947, then released in the belief that he was small fry, Rademacher was finally brought to trial in February 1952 and sentenced to three years and five months for the Serbian massacres. He broke bail in September 1952 and was smuggled out of Europe via Marseilles by a neo-Nazi network, going to Damascus. He could not be extradited from Syria, whose government thoroughly approved of anyone convicted of crimes against the Jews.
In July 1963 Rademacher, however, was imprisoned by the Syrians for allegedly slandering the Syrian State and accused of being a NATO spy, a charge of which he was later acquitted. He suffered two heart attacks and was released from prison in October 1965. He returned penniless to West Germany in September 1966, was re-tried and sentenced to hve-and-a-half years’ imprisonment, but was set free because he had already served part of his total sentence.
In January 1971 the Federal Court in Karlsruhe overruled this verdict and ordered a further trial, but Rademacher died in Bonn on 17 March 1973 before this could take place.