Contrary to the ‘rupture thesis’ favoured in Anglo-American academic discourse, Nazi criminal law did not emerge from a vacuum; nor did it disappear after 1945. The article explains and defends this ‘continuity thesis’. In fact, Nazi criminal law adopted earlier authoritarian tendencies of German criminal law and exacerbated them (the ‘radicalisation thesis’). It is for this reason that Nazi criminal law should not lightly be dismissed as ‘non-law’, thus omitting any further engagement with it. The article will show that the same continuity and radicalisation arguments can be made, mutatis mutandis, for German Nazi criminology, which ultimately became a legitimating science (‘Legitimationswissenschaft’) for Nazi criminal justice policy. The argument is developed in four stages. First, an account is given of the racist and criminal-biologistic foundations of National Socialist criminology, including their continuity both with the past and into the future. This is followed by an explanation of the influence of criminal anthropology (particularly that of Lombroso) on the ‘scientification’ of criminology (the ‘Kraepelin and Aschaffenburg paradigms’). Third, the National Socialist radicalisation of criminology on the basis of the criminal-biological utopia of the ‘blood-based’ Volksgemeinschaft is described. Thus, Nazi criminology derived its strength from and built upon biological theories of crime, which in turn laid the foundations of the deadly Nazi criminal justice policy. The discipline became a science that legitimated National Socialism, contrary to Wetzell's thesis of a somewhat dissident ‘mainstream criminology’. With regard to disturbing developments in current German politics, all this will make clear that the approach of the (German) ‘New Right’ to criminal justice is not novel at all but is derived from the ideologically infused theories and policies of Nazi criminologists during the 1930s.