Abstract

This article represents one of the first comprehensive efforts to elucidate the elements of crimes against humanity. Written in the immediate aftermath of the adoption of the Rome Statute of the ICC, the article identifies startling doctrinal ambiguities in the definition of these crimes. With prosecutions for crimes against humanity underway before two ad hoc international criminal courts and the prospect of many more such trials before the permanent ICC, the dictates of the principle of legality lent urgency to the task of defining these crimes. Furthermore, the chapeau elements of crime against humanity provide the normative basis for international jurisdiction over such crimes. The elaboration of these elements therefore clarifies the circumstances under which international courts may legitimately exercise jurisdiction over crimes that would otherwise fall within the exclusive purview of sovereign States. This article presents legal and normative arguments for a simplified definition of crimes against humanity requiring merely that the constitutive acts be committed with knowledge that they are part of a widespread or systematic attack against civilians. Additional elements included in some articulations of the definition of crimes against humanity are rejected, including the requirements of a nexus to armed conflict and discriminatory intent. The article focuses particular attention on the much-neglected mens real element of crimes against humanity, arguing against the specific intent standard espoused in some of the jurisprudence in favor of a knowledge requirement. A number of the arguments advanced in this article have been adopted in subsequent case law, and the chapeau in the statute of the Special Court for Sierra Leone reflects the definition proposed herein.