The Appeals Chamber considered that the existing standards on appeal necessitated a “further examination”.[1] It first noted the standard of review when additional evidence has been admitted on appeal set out by the Appeals Chamber in Kupreškić:

The test to be applied by the Appeals Chamber in deciding whether or not to uphold a conviction where additional evidence has been admitted before the Chamber is: has the appellant established that no reasonable tribunal of fact could have reached a conclusion of guilt based upon the evidence before the Trial Chamber together with the additional evidence admitted during the appellate proceedings.[2]

The Appeals Chamber then considered that:

23. However, if in a given case, the outcome were that a reasonable trier of fact could reach a conclusion of guilt beyond reasonable doubt, the Appeals Chamber considers that, when the Appeals Chamber is itself seized of the task of evaluating trial evidence and additional evidence together, and in some instances in light of a newly articulated legal standard, it should, in the interests of justice, be convinced itself, beyond reasonable doubt, as to the guilt of the accused, before confirming a conviction on appeal. […]

The Appeals Chamber then summarised the “standard of review to be applied on appeal by the International Tribunal in relation to findings challenged only by the Defence, in the absence of a Prosecution appeal”:

24. (a) The Appeals Chamber is confronted with an alleged error of fact, but the Appeals Chamber has found no error in the legal standard applied in relation to the factual finding. No additional evidence has been admitted on appeal in relation to that finding. The Appeals Chamber will determine whether no reasonable trier of fact could have reached the conclusion of guilt beyond reasonable doubt. If a reasonable trier of fact could have reached such a conclusion, then the Appeals Chamber will affirm the finding of guilt.

(b) The Appeals Chamber is confronted with an error in the legal standard applied in relation to a factual finding, and an error of fact has been alleged in relation to that finding. No additional evidence has been admitted on appeal in relation to that finding. The Appeals Chamber will apply the correct legal standard to the evidence contained in the trial record, and will determine whether it is itself convinced beyond reasonable doubt as to the finding of guilt.

(c) The Appeals Chamber is confronted with an alleged error of fact, and – contrary to the scenario described in (a) – additional evidence has been admitted on appeal. There is no error in the legal standard applied in relation to the factual finding. There are two steps involved.

The Appeals Chamber will first determine, on the basis of the trial record alone, whether no reasonable trier of fact could have reached the conclusion of guilt beyond reasonable doubt. If that is the case, then no further examination of the matter is necessary as a matter of law.

If, however, the Appeals Chamber determines that a reasonable trier of fact could have reached a conclusion of guilt beyond reasonable doubt, then the Appeals Chamber will determine whether, in light of the trial evidence and additional evidence admitted on appeal, it is itself convinced beyond reasonable doubt as to the finding of guilt.

(d) The Appeals Chamber is confronted with an error in the legal standard applied in relation to the factual finding and an alleged error of fact, and – contrary to the scenario described in (b) –  additional evidence has been admitted on appeal. There are two steps involved.

(i) The Appeals Chamber will apply the correct legal standard to the evidence contained in the trial record, and will determine whether it is itself convinced beyond reasonable doubt as to the finding of guilt, on the basis of the trial record. If it is not convinced, then no further examination of the matter is necessary as a matter of law.

(ii) If, however, the Appeals Chamber, applying the correct legal standard to the evidence contained in the trial record, is itself convinced beyond reasonable doubt as to the finding of guilt, it will then proceed to determine whether, in light of the trial evidence and additional evidence admitted on appeal, it is itself still convinced beyond reasonable doubt as to the finding of guilt.

See also the Partial Dissenting Opinion of Judge Weinberg de Roca.

69. The Appeals Chamber also notes that the duty of commanders to report to competent authorities is specifically provided for under Article 87(1) of Additional Protocol I, and that the duty may also be deduced from the provision of Article 86(2) of Additional Protocol I.[1] The Appeals Chamber also notes the Appellant’s argument that to establish that effective control existed at the time of the commission of subordinates’ crimes, proof is required that the accused was not only able to issue orders but that the orders were actually followed. The Appeals Chamber considers that this provides another example of effective control exercised by the commander. The indicators of effective control are more a matter of evidence than of substantive law,[2] and those indicators are limited to showing that the accused had the power to prevent, punish, or initiate measures leading to proceedings against the alleged perpetrators where appropriate.[3] […]

135. The Appeals Chamber considers that “although persecution often refers to a series of acts, a single act may be sufficient, as long as this act or omission discriminates in fact and was carried out deliberately with the intention to discriminate on one of the listed grounds.”[1] Furthermore, the acts underlying persecutions as a crime against humanity, whether considered in isolation or in conjunction with other acts, must constitute a crime of persecutions of gravity equal to the crimes listed in Article 5 of the Statute.[2]

138. The Appeals Chamber considers that the Trial Chamber failed to mention that acts of persecutions, considered separately or together, should reach the level of gravity of other crimes listed in Article 5 of the Statute. It appeared to consider, erroneously, that underlying acts are rendered sufficiently grave if they are committed with a discriminatory intent.

160. The Appeals Chamber considers that a Trial Chamber, when making a determination on a charge of persecutions, is obliged to assess whether the underlying acts amount to persecutions as a crime against humanity in international customary law. Upon consideration of the Trial Chamber’s outline of the applicable law on persecutions, it is evident that the Trial Chamber did not consider the requirement that acts of persecutions must be of an equal gravity or severity as the other acts enumerated under Article 5 of the Statute; it is not enough that the underlying acts be perpetrated with a discriminatory intent. […]

186. It is, therefore, evident, both from the text of Article 4(2)[1] and the accompanying Commentary, that for Article 4(2) to be relevant, it must be demonstrated, first, that the States were allies, and second, that they enjoyed effective and satisfactory diplomatic representation with each other. In contrast, the Appellant submits that the Trial Chamber should have ignored the fact that “HVO and ABiH forces, at times, fought each other” and looked simply at the “formal diplomatic relations” between the two States.[2] Such an approach is not only inconsistent with the object and purpose of Article 4 of Geneva Convention IV, that is, “the protection of civilians to the maximum extent possible”,[3] but also conflates the distinction between co-belligerence and diplomatic representations.

187.    The Appellant makes no attempt to reconcile the apparent contradiction between the status of belligerent and that of co-belligerent, but instead refers the Appeals Chamber to allegedly “uncontroverted evidence establishing co-belligerence and diplomatic relations” between the two States.[4] The language of Article 4 of Geneva Convention IV is not so elastic as to allow the conclusion that two States could simultaneously be allies and belligerents with each other. In this case, the States of Croatia and Bosnia-Herzegovina were engaged in a conflict against each other. This, in itself, establishes that they were not co-belligerents within the meaning Article 4(2) for the purpose of crimes arising out of that conflict.

30. Pursuant to Rule 66(A)(ii) of the Rules, the Prosecutor has a duty, inter alia, to make available to the Defence copies of the statements of all witnesses whom the Prosecutor intends to call to testify at trial. The Appeals Chamber notes that neither the ICTR nor ICTY has provided a clear definition of the term “statement.” In particular, the jurisprudence has not made a clear distinction between “statements” and “internal documents prepared by a party [which] are not subject to disclosure or notification”[1] under Rules 66 and 67 of the Rules.[2]

31. A record of a witness interview, ideally, is composed of all the questions that were put to a witness and of all the answers given by the witness. The time of the beginning and the end of an interview, specific events such as requests for breaks, offering and accepting of cigarettes, coffee and other events that could have an impact on the statement or its assessment should be recorded as well.

32. Such an interview must be recorded in a language the witness understands. As soon as possible after the interview has been given, the witness must have the chance to read the record or to have it read out to him or her and to make the corrections he or she deems necessary and then the witness must sign the record to attest to the truthfulness and correctness of its content to the best of his or her knowledge and belief. A co-signature by the investigator and interpreter, if any, concludes such a record.

33. Records of questions put to witnesses by the Prosecution and of the answers given constitute witness statements pursuant to Rule 66(A)(ii) of the Rules. It is necessary to disclose the questions put to the witness in order to make the statement intelligible. This obligation also follows from the fair trial guarantees stipulated in Articles 19 and 20 of the Statute. Furthermore, an accused must have access to the questions put to the witness in order to be able to prepare for cross-examination properly. At times, it may be impossible to assess the probative value of the witness’s answer without juxtaposing it with the relevant question. This may also affect a Chamber’s assessment of the credibility of the witness and the reliability of a testimony in its development. The record of the first interview with a witness is of the highest value because it is most likely to capture the witness’s recollection accurately, being closest in time to the events and less vulnerable to any subsequent influence.

34. Questions that were put to a witness – thus being part of the witness statement – have to be distinguished from “internal documents prepared by a party”,[3] which are not subject to disclosure under Rule 70(A) of the Rules, as an exception to the general disclosure obligation pursuant to Rule 66(A)(ii) of the Rules. A question once put to a witness is not an internal note any more; it does not fall within the ambit and thereby under the protection of Rule 70(A) of the Rules. If, however, counsel or another staff member of the Prosecution notes down a question prior to the interrogation, without putting this question to the witness, such a question is not subject to disclosure. Similarly, any note made by counsel or another staff member of the Prosecution in relation to the questioning of the witness is not subject to disclosure, unless it has been put to the witness.

35. The fact that a particular witness statement does not correspond to the standard set out above does not free a party from its obligation to disclose it to the other party pursuant to Rule 66(A)(ii) of the Rules. Furthermore, a witness statement which does not correspond to the standard set out above does not necessarily render the proceedings unfair. The Prosecution is obliged to make the witness statement available to the Defence in the form in which it has been recorded. However, something which is not in the possession of or accessible to the Prosecution cannot be subject to disclosure: nemo tenetur ad impossibile (no one is bound to an impossibility).[4]

36. Also, a statement not fulfilling the ideal standard set out above is not inadmissible as such. Pursuant to Rule 89(C) of the Rules, a Chamber may admit any relevant evidence which it deems to have probative value. However, any inconsistency of a witness statement with the standard set out above may be taken into consideration when assessing the probative value of the statement, if necessary.

198. In considering whether a defect in the indictment has been cured by subsequent disclosure, the question arises as to which party has the burden of proof on the matter. Although the Judgement in Kupreškić did not address this issue expressly, the Appeals Chamber’s discussion indicates that the burden in that case rested with the Prosecution. Kupreškić stated that, in the circumstances of that case, a breach of “the substantial safeguards that an indictment is intended to furnish to the accused” raised the presumption “that such a fundamental defect in the … Indictment did indeed cause injustice.”[1] The defect could only have been deemed harmless through a demonstration “that [the Accused’s] ability to prepare their defence was not materially impaired.”[2] Kupreškić clearly imposed the duty to make that showing on the Prosecution, since the absence of such a showing led the Appeals Chamber to “uph[o]ld the objections” of the accused.[3]

14. The Tribunal’s instruments do not prescribe qualification requirements for members of the staff of the Office of the Prosecutor appearing before it. While Rule 44(A) of the Tribunal’s Rules of Procedure and Evidence (“Rules”) stipulates that a counsel engaged by a suspect or an accused “shall be considered qualified to represent a suspect or accused, provided that he is admitted to the practice of law in a State, or is a University professor of law,” the Rules and other instruments of the Tribunal contain no corresponding qualification provision for Prosecution counsel. In consequence, the integrity of the trial process before the Tribunal cannot be undermined, per se, by the status a Prosecution counsel may or may not have as a member of the bar in any State.

45. Following the Judgement of the ICTY Appeals Chamber in the case of Prosecutor v. Furundžija, the Appeals Chamber held in Akayesu that “there is a presumption of impartiality that attaches to a Judge or a Tribunal and, consequently, partiality must be established on the basis of adequate and reliable evidence.”[1] On appeal, it is for the appealing party to rebut this presumption of impartiality. As stated in Furundžija in respect of a reasonable apprehension of bias, the Appellant bears the burden of adducing sufficient evidence to satisfy the Appeals Chamber that the Judges were not impartial.[2] In Furundžija the ICTY Appeals Chamber held that there is “a high threshold to reach in order to rebut the presumption of impartiality” and recalled that “disqualification is only made out by showing that there is a reasonable apprehension of bias by reason of prejudgement and this must be ‘firmly established’”.[3] The Appeals Chamber recently confirmed this position in the Judgement in the case of Rutaganda v. Prosecutor.[4]

98. The ordinary meaning of the term “accomplice” is “an associate in guilt, a partner in crime.”[1] Nothing in the Statute or the Rules of the Tribunal prohibits a Trial Chamber from relying upon testimony of those who were partners in crime of persons being tried before it. As stated above, a Chamber may admit any relevant evidence which it deems to have probative value.[2] Accomplice testimony is not per se unreliable, especially where an accomplice may be thoroughly cross-examined.[3] However, considering that accomplice witnesses may have motives or incentives to implicate the accused person before the Tribunal, a Chamber, when weighing the probative value of such evidence, is bound to carefully consider the totality of the circumstances in which it was tendered.[4] In the view of the Appeals Chamber, reliance upon evidence of accomplice witnesses per se does not constitute a legal error.