The editors of this journal have asked me to write a short reply to Karemaker Taylor, and Pittman.Footnote ¹ Although I have already explained my position with respect to the subject under dispute elsewhere,Footnote ² I have accepted this invitation given the importance of the topic and the great influence of the Leiden Journal in international criminal law circles. I have some serious objections with regard to the position echoed by Karemaker et al., since it starts in some parts from incorrect assumptions and it is, in the overall assessment of proofing, seriously flawed and unconvincing. My remarks will focus on the legality and necessity of this practice with regard to the International Criminal Court (ICC).

1. At the beginning of their paper (section 2) the authors consider proofing as ‘a necessary adjunct of the adversarial criminal trial’: ‘[b]ecause the evidence presented at trial is the basis on which the fact finder will establish what happened, the manner in which that evidence is presented is of paramount importance.’ While it is true that proofing is unknown in civil law systems and while one may even argue that, in turn, this practice is a necessary ingredient of adversarial criminal proceedings, the importance of the (public) trial with respect to the assessment of the evidence by the judges (or jurors) as to the facts before them is common to both systems. Thus the reason that proofing exists in the one system but not in the other does not hinge on the importance of the trial but can only be explained by the structural difference of these systems with regard to the production and presentation of evidence. While in an adversarial system the evidence is produced and presented by the parties, civil law systems are essentially judge-led and, in this sense, rather inquisitorial in nature.Footnote ³ For such systems any preparation of witnesses with regard to the presentation of evidence – that is, proofing – would be a structural contradiction, since they do not know witnesses of either party but only witnesses of the truth.Footnote ⁴ This is what I call the underlying ‘system dimension’ of proofing. We shall come back to this point (infra, 3).

2. Turning to the international criminal tribunals this means that proofing would certainly produce no structural frictions if these tribunals followed a purely adversarial system. While this is certainly true for the ad hoc tribunals (the International Criminal Tribunal for the former Yugoslavia (ICTY), the International Criminal Tribunal for Rwanda (ICTR), and the Special Court for Sierra Leone (SCSL)), which, despite important amendments to the Rules of Procedure and Evidence (RPE) with a view to a more ‘inquisitorial’ procedure, are still adversarial in nature and practice and therefore wholeheartedly approve the practice of witness proofing, the drafters of the ICC Statute always wanted to create a truly mixed procedure, taking in elements from both systems, and they indeed succeeded in doing so. This may be demonstrated, as I have done elsewhere,Footnote ⁵ by examining various provisions of the Statute and by an analysis of the structure of the pre-trial and trial procedure. It is not clear what position Karemaker et al. take in this respect. While they rightly recognize the adversarial origins of the ad hoc tribunals (section 2), they do not explicitly characterize the ICC's procedure in one way or the other. Their reference to proceedings in Spain, Belgium, and Germany as ‘fundamentally different’ from the ICC (n. 33)Footnote ⁶ at least seems to imply that they do not consider the ICC procedure to be an inquisitorial one. In fact, it seems as if they do not really care what the existing law of the ICC says, since this law is, in their view, inconclusive as to our questionFootnote ⁷ and, even if it clearly prohibited proofing, ‘the comparative advantages of proofing would legitimize serious contemplation of legislative reform’ (section 5; we shall turn to this argument infra, 4.b).Footnote ⁸

3. It is not possible, however, to push the legal questions involved aside so lightly. In fact, the contention within the ICC has been one of both legal and policy considerations and, indeed, the Office of the Prosecutor (OTP) has tried to demonstrate, albeit with unconvincing arguments, that proofing has a legal basis in the Statute.Footnote ⁹ The reason for this struggle between the OTP and the (pre-trial and trial) chambers about a possible legal basis of proofing in the Statute is linked to the above-mentioned system dimension of proofing. If proofing is only possible in purely adversarial systems and the ICC Statute does not constitute such a system (but a mixed one), proofing is only possible before the ICC if it is provided for, at least implicitly, in its governing law. As this is not the case, not even on the basis of a general principle according to Article 21(1)(c) of the ICC Statute, as demonstrated elsewhereFootnote ¹⁰ and correctly asserted by the pre-trial and trial chambers,Footnote ¹¹ the discussion is over at this point with respect to the lex lata. All that follows is a pure policy discussion de lege ferenda with a view to possible reforms of the ICC Statute.

4. As has been said, Karemaker et al. are essentially concerned with these de lege ferenda policy considerations. Yet in this respect also their arguments are partly flawed and partly simply unconvincing.

4.a. They argue that proofing is not rehearsing, coaching, and so on (section 5.2.1). Yet the experience in common law jurisdictions shows that such a clear-cut distinction between the permitted and the prohibited witness preparation does not work in practice. Thus in the United States the difficult question of where to draw the line between permitted preparation (in the sense of familiarization) and prohibited coaching (in the sense of altering ‘a witness's story about the events in question’Footnote ¹²) has generated an intense debate about the ethical limitations of witness preparation,Footnote ¹³ a debate which goes back to the famous dictum of Judge Francis Finch of the New York Court of Appeals in 1880, when it was held:

It is puzzling that Karemaker et al. ignore this practice, given that the United States is the most important and probably the only (common law) jurisdiction where proofing is practised on a daily basis and without a comprehensive set of rules (as, for example, exists in England and Wales).Footnote ¹⁵ In fact, the practice has for some scholars touched upon the very foundations of the US criminal justice system:

4.b. In fact, the practical experiences with proofing in common law jurisdictions, especially the United States, also raise doubts as to the ‘comparative advantages of proofing’ adduced by Karemaker et al. (section 5.2.2). The argument that proofing produces more complete and comprehensive evidence is highly questionable, given the serious risks of manipulation involved in this practice. Obviously, a well-prepared witness who only repeats the statement previously trained in extenso with the prosecutor or the defence lawyer will probably produce more evidence in quantitative terms and her presentation may also appear comprehensive and consistent, but this does not say anything about the quality of this evidence, especially with a view to the truth-seeking function of the trial. In other words, the prima facie convincing, because well presented, evidence of a proofed witness may after a more detailed examination of her statement readily turn into pseudo-evidence, since it does not tell the truth but rather manipulates the facts. But how will the judges find out whether the proofing of such a witness was excessive or whether she was just well prepared? How will they find out the truth of her statement if she presents it without contradictions and gaps in such a perfect manner? In fact, precisely with a view to the truth of a witness statement, beyond all show elements of US jury trials, the spontaneous witness is much more useful than the proofed witness since spontaneity guarantees authenticity. This is the very reason why the trial chamber refers to the ‘helpful spontaneity during the giving of evidence by a witness’Footnote ¹⁷ and this is, contrary to Karemaker et al., not ‘puzzling’ (section 5.2.2) but in full harmony with a concept of ‘witnesses of the court’ instead of ‘witnesses of either party’.Footnote ¹⁸

4.c. The risks involved in proofing, also acknowledged by Karemaker et al. (section 5.2.3), may be mitigated by the factors suggested by the authors (section 5.3), but they cannot be outweighed to such a degree that proofing can be considered to be an acceptable practice. Admittedly, this is a value judgement strongly influenced by the legal background of each author (including this one), but I simply fail to see that the objective risks of proofing are counterbalanced by its suggested advantages because I do not see these advantages; on the contrary, I think the practice presents serious disadvantages (supra, 4.b). In addition, Karemaker et al. expect too much from their suggested mitigating factors:

4.c.i. The efficacy of cross-examination (section 5.3.1) to verify the authenticity of a statement of a proofed witness is, to say the least, doubtful;Footnote ¹⁹ for some common law scholars this expectation is ‘nothing more than an article of faith’.Footnote ²⁰ Be that as it may, cross-examination is not common practice before an international criminal tribunal that, like the ICC, has a mixed procedure, and it will only be practised efficiently by common lawyers who are familiar with this practice. Consequently, to require cross-examination as a method to control proofing would limit this control to one group of lawyers appearing before the ICC.

4.c.ii. The superiority of professional judges over lay jurors (section 5.3.2) as to the verification of the authenticity of a witness statement – that is, a question of fact – is also highly doubtful. In fact, the involvement of lay persons in the criminal justice process, be it as jurors or as members of a mixed bench, rests on the belief that these persons are, due to their professional or social background, often in a better position to judge the veracity of a witness statement.Footnote ²¹ In addition, the superiority argument rests on the false assumption that the judges of international criminal tribunals are all professional judges. The sad reality is, however, that too many judges have no judicial background at all and only pass the eligibility test (Art. 36(3)(b) ICC Statute) because of an all-too-generous interpretation of the requirement of ‘competence in relevant areas of international law’ (Art. 36(3)(b)(ii) ICC Statute).Footnote ²²

4.c.iii. Codes of professional conduct (section 5.3.3) may help, but they do not, as correctly argued by Karemaker et al., ‘alone prevent ethical breaches’. Again, the problem lies in the problematic distinction between permitted and prohibited witness preparation. Codes that want to grasp this fine distinction must be very specific and precise (as the English experience shows) or they contain provisions that are too general (as, e.g., the American Bar Association's Model Rules of Professional Conduct) really to serve as clear guidance.Footnote ²³

4.c.iv. Finally, the contempt power (section 5.3.4) is a typical adversarial feature which goes hand in hand with the prominent role of the parties in producing evidence. It does not fit well in a mixed procedure as the one before the ICC, and, indeed, Article 70(1) of the ICC Statute does not provide for a contempt power, as incorrectly suggested by Karemaker et al. (n. 92), but only for the Court's jurisdiction with regard to offences against the administration of justice. These offences are part and parcel of any national criminal justice system and therefore Article 70(4) obliges the states parties to extend the scope of their (national) offences to the acts mentioned in Article 70(1) if committed on their territory or by one of their nationals. Also, the commission of one of the offences under Article 70(1) will lead to an autonomous investigation, prosecution, and trial (cf. Rule 165 of the ICC's RPE), i.e., contrary to the contempt of court procedure, the sanction will not be imposed by the same trial chamber. In this respect, Article 71 of the ICC Statute, providing for sanctions for misconduct before the Court, is rather comparable to the ad hoc tribunals' contempt of court power, but it is, in terms of the sanctions (basically administrative measure to preserve the order of the proceedings), not as far-reaching as this power.

5. In conclusion, all these arguments demonstrate that witness proofing is, before the ICC, neither legally admissible nor a necessary and useful practice. As to the necessary preparation of witnesses to enable them to give oral evidence at trial in a satisfactory manner – that is, preparation in the sense of familiarization Footnote ²⁴ – the ICC's Victims and Witnesses Unit can adequately fulfil this task.Footnote ²⁵