Bringing criminals to justice before any court requires a complex body of procedural law. In addition to the procedures needed for conducting the trial as such, the Rome Statute contains procedures for raising, considering and determining the admissibility of cases as well as procedures for their final selection. The complementarity principle can only function as envisaged with detailed procedures in place. Collisions with national jurisdictions will force the International Criminal Court (ICC) Prosecutor into disputes with states which will raise questions very different from those normally associated with criminal proceedings. Sophisticated forms of interaction between states and the Court, unprecedented in the field of international criminal justice, and possibly in any other field of international law, are required. The Rome Statute's procedural regime must address, inter alia, how the Prosecutor may detect national failure to proceed genuinely; how information may flow between the Prosecutor and states; at what stage, how and by whom the admissibility may be challenged; and how and by whom admissibility disputes are to be settled. The complementarity procedures represent a compromise between the need to ensure the ICC's effectiveness and the need to preserve state sovereignty. This dichotomy is even more apparent here than in the substantive provisions. Addressing two inherently conflicting concerns has resulted in a set of rules that is not always equally comprehensive.

Introduction

As noted by Pre-trial Chamber I, the Rome Statute's admissibility test covers two aspects: first, a case is inadmissible if it has been genuinely investigated or prosecuted by a state with jurisdiction over it. Second, the case must be of sufficient gravity. This chapter primarily treats the first aspect, but most of the same proceedings apply also with regard to the second aspect. The discussion is based on a reading of the relevant provisions in the Statute and the Rules of Procedure and Evidence (RPE), in light of the ICC's first years of practice and relevant literature.