This article describes the development of research into criminal prognostics and corresponding instruments in Germany in the period following the seizure of power by the National Socialists, not least in the context of the establishment of prophylactic imprisonment for "habitual offenders" and the incorrigible. Stimulated by the American sociologically working criminology, standardized and simple prognostic instruments were developed in Germany, which were considered to be superior to the allegedly "intuitive" criminal prognostics. The article describes the control and modifications which were undertaken and the discussion at that time between supporters of individual prognosis and supporters of conclusions drawn from group statistics. It has been proven that certain core problems have remained unaltered and that methodological questions also lead to questions of legal policy.