(Ir)retroactividad de las modificaciones a la norma complementaria de una ley penal en blanco

Abstract

The author, starting from the nullum crimen nulla poena sine lege principle, explains the scope of the legality principle for criminal laws in blank, stating that they must contain the main verb of the conduct and its subjective aspect, thus allowing their completion through statutory norms. Recognizing legal certainty as the basis for irretroactivity of criminal laws, and proportionality and necessity of punishment as a justification for more benign criminal law retroactivity, shows the underlying retroactive application problems of amending the statutory norm.