Editor’s Note: This is the second of a three-part series regarding the ICC’s Independent Expert Review, the crossroads at which the ICC finds itself, and issues that lie ahead for the Court. Part I is available here

Part I of this series discussed portions of the recent report of the International Criminal Court (ICC) Independent Experts that addressed the need for the ICC to narrow its aperture, and potential implications of this observation related to the Court’s treatment of “gravity” and “the interests of justice.” The Independent Experts gave some – but not as much – attention to the issue of “complementarity,” but the report’s ideas regarding this issue were not focused on the possibilities for using complementarity in a way that would help Court actors make the difficult choices about where to focus their energy and resources.


The basic idea of complementarity is that the ICC is a court of last resort, and that it should not pursue the investigation or prosecution of cases unless the relevant State is unable or unwilling to do so. The idea is seemingly straightforward but its application can present significant conceptual difficulties. For example, what happens if the relevant State:

  • pursues different cases against the accused persons (like when the U.S. government prosecuted Al Capone for the relatively mundane crime of tax evasion, rather than the more heinous underlying crimes that he was suspected of having committed, but that would have been harder to prove in court).
  • does not pursue a case, or pursues a case against a different person than the Prosecutor has in mind, but does so for reasons separate from a desire to shield wrongdoers. Should it be sufficient if the domestic prosecutor in an otherwise well-functioning judicial system chose not to pursue an investigation or prosecution for reasons separate from any desire to shield an accused person – g., because key witnesses were not credible, because essential evidence was not admissible, because doing so might endanger witnesses, or because of other feasibility issues of this type that – under the ICC Prosecutor’s own approach – might result in the Prosecutor herself “hibernating” a case?
  • is willing and able to pursue cases but needs time to organize itself to do so. It is not hard to imagine situations in which it may take many years for a State to build the domestic capacity to pursue relevant cases, such as in post-conflict transitional justice settings in which basic judicial and prosecutorial capacity needs to be developed, and yet the eventual investigation and prosecution domestically of the relevant crimes may be an important part of the process of national healing and rule of law development.

It is only on this third category that the Experts weighed in, but they do so in the context of a different problem faced by the Prosecutor. Specifically, the Experts address this issue in the context of criticisms about the Prosecutor’s preliminary examinations carrying on inconclusively for too long. From this perspective, if the Prosecutor is in the position of having to await the outcome of a years-long transitional justice process, she may be forced to keep the preliminary examination open for years. The Experts thus recommended that, in thinking about the complementarity issue, the Prosecutor “should not have regard to prospective national proceedings and should focus solely on whether national proceedings are or were ongoing” or have already been completed.

To be sure, this approach would help the Prosecutor shorten the length of preliminary examinations. It could also help ameliorate some of the political tension between the ICC Office of the Prosecutor (OTP) and situation States that is frequently associated with the need for the Prosecutor to continually assesses whether the situation State is genuinely trying to put itself in a position to prosecute, or whether it is engaged in a game of rope-a-dope to fend the Court off.

At the same time, however, ICC treatment of a State’s genuine steps in the direction of accountability as insufficient would result in a larger number of preliminary examinations quickly evolving into formal investigations. Thus, while this approach might result in the Prosecutor having fewer preliminary examinations open at any particular time, it may simultaneously result in more open investigations. The approach may not serve the broader objective of rendering the Prosecutor less over-extended, and it could easily interfere with the objectives of contributing to the strengthening of domestic systems and encouraging States to take the lead on the prosecution of crimes within their midst.

In any event, the Experts’ recommendation addresses only the third of the three types of situations that I describe above, and does not address other possibilities for conceptualizing complementarity in ways that could address the need for the ICC to better prioritize. For example, with respect to the first type of situation described above, it undoubtedly would have served important societal interests to prosecute Al Capone for the underlying crimes of concern. But a prosecution for tax evasion might well have represented a good-faith decision by a principled prosecutor who must balance that particular societal interest with – for example – a significantly higher prospect for actually obtaining a conviction.  Indeed, OTP itself has made decisions of this kind, such as when it pursued its first defendant, Thomas Lubanga, on easier-to-prove charges of conscription and use of child soldiers, and not for the broader array of allegations of rape, murder, pillage, sexual violence and other crimes committed by Lubanga’s forces that many considered more heinous. Thus, even assuming that the decision to pursue lesser charges was sub-optimal, it is not obvious that this is the kind of thing that an institution of limited resources like the ICC should attempt to right, at least in the absence of some kind of showing that the decision to pursue the lesser charges was taken in bad faith.

Similarly, with respect to the second type of situation described above, a good-faith prosecutor might well decide not to pursue an investigation or prosecution for a variety of reasons having nothing do with a goal of shielding individuals from prosecution. For example, the Prosecutor might decide that a matter could not be pursued without unduly jeopardizing the safety of witnesses; or that the witnesses whose testimony is needed are not credible, have died, or are otherwise unavailable; or that there were other circumstances that would make it impossible as a practical matter to pursue the case successfully. Admittedly, situations like this can make for uncomfortable hypotheticals, but it would seem appropriate to carefully consider the deference that should be accorded such decisions in thinking about how to find the optimal workload for the Court.

In sum, Court actors might more proactively use complementarity to distinguish among situations in which the reason for the inactivity itself involves bad faith and situations in which it does not. That is not to say that even the situations in which the inactivity does not involve bad faith should necessarily escape international concern, but rather that the ICC might do more to take the distinction into account in deciding where to allocate its resources and efforts in a world where there are already far more potential cases than it can be reasonably be expected to address.

The Complementarity Burden of Proof

The discussion above addressed whether the investigative and prosecutorial steps taken by a State are sufficiently genuine, such that a situation or case should be treated as inadmissible on complementarity grounds. But a separate question involves the burden of proof: to what extent should the burden lie on the State to demonstrate that it has undertaken genuine investigations or on the Prosecutor to demonstrate that it has not? And should the analysis of this question take account of whether the State in question has ratified the Rome Statute?

The ICC’s stated position on this is clear but not beyond debate. For example, as set out by an Appeals Chamber in the situation involving Kenya, a State party, the judges said:

a State that challenges the admissibility of a case bears the burden of proof to show that the case is inadmissible. To discharge that burden, the State must provide the Court with evidence of a sufficient degree of specificity and probative value that demonstrates that it is indeed investigating the case. It is not sufficient merely to assert that investigations are ongoing.

There is an appeal to the logic that the State will almost always have better access than the Prosecutor to information about investigations and prosecutions by its authorities, and the Prosecutor’s view has been that it is fair to draw adverse inferences if the State then fails to substantiate that the proceedings were in fact genuine.

At the same time, the allocation of the burden of proof in this manner is in tension with what some would say should be a presumption of ordinariness – in other words that prosecutors should not be presumed to have acted in bad faith in the absence of an affirmative showing. This in turn could be seen as consistent with the idea that the ICC should limit its involvement to those situations most demonstrably in need of remediation. The issue thus concerns not just the question whether and when it is appropriate to automatically draw adverse inferences, but also the question whether proceeding on such a basis is supportive of the notion that the ICC needs to be more aggressively filtering cases in which it should involve itself.

For Rome Statute parties, which owe cooperation duties toward the Court, the fact that the State is withholding information, and thus failing to meet its responsibilities under the Rome Statute to explain its actions, may support an adverse inference. But the situation might be different for a non-party, which will not have undertaken a commitment to make whatever changes might be needed in its domestic procedures to enable it to comply with such requests.

Consider, for example, a State that has longstanding restrictions against disclosing grand jury material – established for reasons having nothing to do with shielding potential ICC defendants – that block it from sharing information that would persuade the ICC that that a State’s investigation had been conducted in a genuine manner. Is it appropriate for the ICC to draw a negative inference from a refusal to release such grand jury records? And might this determination be different if the State in question is not a party to the Rome Statute? Each case would of course depend on its own facts, but it is an issue worthy of attention.

Other complications may arise because of the order in which events play out. For example, consider a State that places great importance on warding off a preliminary examination before it evolves into a formal investigation. At the point the investigation would commence, the Prosecutor may not be willing to reveal – indeed, the Prosecutor may not yet know – the identity of the defendants against whom it will bring charges. But if this is so, how can the relevant State discharge an obligation to demonstrate that it has already investigated the potential defendants?

Even this brief discussion of questions about complementarity demonstrates that the Experts addressed only a small slice of the issues that could potentially be considered that are related to the aperture issue.  That said, the work of the Experts is not the entire game, and the Experts’ mandate was itself crafted in recognition of the fact that consideration of other key aspects of the  issues would be ongoing in other fora, including the Hague Working Group on Complementarity.

A Working Group report from June reflects a more searching examination about how complementarity should work. It includes a discussion of the perceived flaws that have been encountered in how the Court has managed complementarity, and of its underlying importance to the Rome Statute system. The Working Group process involves a mix of States, some of which are significantly more interested than others in a fresh examination of these issues, but perhaps the important point for present purposes is that discussion of these issues is on the table, even if it is a different table.

IMAGE: Exterior View of new International Criminal Court building in The Hague. (Photo by Michel Porro/Getty Images)