Bolette Frydendahl Larsen explores the history of defining female juvenile delinquency through the emergence of the notion of psychopathy in the re-education of girls in interwar Denmark. The chapter argues that the category of psychopathy was used in the pragmatic management of the girls in re-education and that it also enabled a call for increased resources to solve the problem of female juvenile delinquency. Contrary to most studies of psychopathy, this analysis takes into account not only discursive formations within psychiatry and among professionals in residential care, but also the institutional resources and practices in the specific settings in which the category was used.