Prof. William Schabas noted already in March 2009 the motion of the defence counsel of Katanga challenging the admissibility of the case. He wrote in June about the Trial Chamber II decision to dismiss the challange. This was the most detailed decision on admissibility and the principle of complementarity. The complementarity principle on which the International Criminal Court (ICC) is based entails that the ICC can only investigate and prosecute core international crimes when national jurisdictions are unable or unwilling to do so genuinely. The issue in Katanga and Chui is that the Katanga were arrested by the Democratic Republic of Congo (DRC) and later transferred to the ICC. Thus, one could argue that the DRC was able and willing to investigate and prosecute the case, which would block the ICC from exercising its jurisdiction.
The decision has now been translated to English and it is interesting to read. The Chamber noted "that there is no disagreement between the participants as to the consequence that must be drawn from the demonstrated inaction on the part of the authorities of the DRC. In their opinion, the case would thus be automatically admissible." (para. 21) The Chamber had to examine at what the stage the motion challenging admissibility could be brought. According to article 19(4) of the Rome Statute, this must be done before the "commencement of the trial". Does this mean before the Trial Chamber proceedings commence or even before the proceedings of confirmation of charges has ended? The Chamber relied on the prepatory works when it came to the conclusion that "after the confirmation of charges, only challenges based on article 17(1)(c) of the Statute are allowed" (para. 47) Article 17(1)(c) concerns the ne bis in idem principle. The Chamber summarized it in para. 49:
In sum, the Chamber considers that the Statute provides a three‐phase approach in respect of challenges to admissibility. During the first phase, which runs until the decision on the confirmation of charges is filed with the Registry, all types of challenges to admissibility are permissible, subject to the requirement, for States, to make them at the “earliest opportunity”. In the second phase, which is fairly short, running from the filing of the decision on the confirmation of charges to the constitution of the Trial Chamber, challenges may still be made if based on the ne bis in idem principle. In the third phase, in other words, as soon as the chamber is constituted, challenges to admissibility (based only on the ne bis in idem principle) are permissible only in exceptional circumstances and with leave of the Trial Chamber.Considering that the Motion of the Defence was late the Chamber stated that it should normally be declared inadmissible. However, for the various reasons, the Chamber considered it appropriate to rule on the merits of the Motion. These reason included the ambiguity of the provisions of the Statute and of the Rules (paras. 56-58)
The Chamber stated that "the Prosecutor is not required to provide the Pre‐Trial Chamber with “the necessary factual information to determine the admissibility of the case” when requesting the issuance of a warrant of arrest." (para. 65)
The Chamber also noted that "[t]he provisions of article 17 of the Statute must be read in light of paragraph 10 of the Preamble and article 1 of the Statute. Read together, these provisions establish one of the fundamental principles of the Statute, namely that the Court is complementary to national criminal courts. Thus, according to the Statute, the Court may only exercise its jurisdiction when a State which has jurisdiction over an international crime is either unwilling or unable genuinely to complete an investigation and, if warranted, to prosecute its perpetrators." (para. 74) The Chamber considered "that a State which chooses not to investigate or prosecute a person before its own courts, but has nevertheless every intention of seeing that justice is done, must be considered as lacking the will referred to in article 17." (para 77) The Chamber noted "the clear and explicit expression of unwillingness of the DRC to prosecute" the case, (para. 95) rejected the motion and the case against Katanga admissible.
In my view, this is a important decision not only for this specific case but also for future cases at the ICC. The conslusion in para. 77 means that states who in principle are willing and able to prosecute can choose not do so and the cases will still be admissible before the ICC.