The Appeals Chamber held in paragraph 19 of the decision that:

19. Rules 15bis (D) of the Rules confers on the remaining Judges the discretion to determine whether to continue the trial proceedings with a substitute Judge. In exercising this discretion, the remaining Judges have “the right to establish the precise point within a margin of appreciation at which a continuation [of the proceedings] should be ordered”.[1] The Appeals Chamber has previously stated that it can only intervene in this decision-making process in limited circumstances, as, for example, where it is of the view that there was a failure to exercise the discretion, or that the remaining Judges failed to take into account a material consideration or took into account an immaterial one and that the substance of its decision has in consequence been affected.[2] It is not enough to show that the Appeals Chamber would have exercised the discretion differently.[3]

19. […] The Trial Chamber considered the “particular circumstances” of Mr. Šešelj’s representation including the fact that he is “not officially assisted by persons fluent in one of the official languages of the Tribunal”,[1] and whether disclosure of Rule 66 (A) and (B) and Rule 68 (i) and (ii) materials in English and in electronic format would affect Mr. Šešelj’s rights under Article 21 of the Statute. It held that electronic disclosure of Rule 66 (A) and (B) and Rule 68(i) materials did not breach the fair hearing principle stipulated under Article 21 of the Statute so long as reasonable and necessary assistance in the circumstances is given to an accused and noted that Mr. Šešelj would be “entitled to receive from the Registry the basic equipment and training necessary to make effective use of material disclosed in electronic format”.[2] It also ruled that in addition to Rule 66(A) material, which expressly provides for disclosure in a language the accused understands, Rule 68(i) material should also be subject to the same language requirement, because of the crucial impact of such material on the accused’s guilt or innocence.[3] Mr. Šešelj does not provide any references to the jurisprudence that the Trial Chamber allegedly disregarded in reaching the Impugned Decision. Neither does Mr. Šešelj demonstrate in what way the Impugned Decision violated his rights under Article 21 of the Statute.

With regard to aiding and abetting by omission proper, the Appeals Chamber declined to discuss this mode of responsibility in detail, but recalled:

274.    […] The Appeals Chamber has recently affirmed that omission proper may lead to individual criminal responsibility under Article 7(1) of the Statute where there is a legal duty to act.[1] However, it has never set out the requirements for a conviction for omission in detail,[2] and it has so far declined to analyse whether omission proper may lead to individual criminal responsibility for aiding and abetting.[3]

The Trial Chamber had held that a conviction for a crime under the JCE doctrine requires that the person actually committing the actus reus of the crime (“principal perpetrator”) is a member of the same criminal enterprise. The Appeals Chamber reversed this finding and found:

410.    […] that what matters in a first category JCE is not whether the person who carried out the actus reus of a particular crime is a member of the JCE, but whether the crime in question forms part of the common purpose.[1] […]

411.    When the accused, or any other member of the JCE, in order to further the common criminal purpose, uses persons who, in addition to (or instead of) carrying out the actus reus of the crimes forming part of the common purpose, commit crimes going beyond that purpose, the accused may be found responsible for such crimes provided that he participated in the common criminal purpose with the requisite intent and that, in the circumstances of the case, (i) it was foreseeable that such a crime might be perpetrated by one or more of the persons used by him (or by any other member of the JCE) in order to carry out the actus reus of the crimes forming part of the common purpose; and (ii) the accused willingly took that risk – that is the accused, with the awareness that such a crime was a possible consequence of the implementation of that enterprise, decided to participate in that enterprise.

[…]

413.    […] [T]he Appeals Chamber finds that, to hold a member of a JCE responsible for crimes committed by non-members of the enterprise, it has to be shown that the crime can be imputed to one member of the joint criminal enterprise, and that this member – when using a principal perpetrator – acted in accordance with the common plan. The existence of this link is a matter to be assessed on a case-by-case basis.[2]

At the end of its discussion, the Appeals Chamber summarised the requirements for a conviction under the JCE doctrine. Apart from the requisite intent (para. 429), these requirements were enumerated as follows:

430.    […] A trier of fact must find beyond reasonable doubt that a plurality of persons shared the common criminal purpose; that the accused made a contribution to this common criminal purpose; and that the commonly intended crime (or, for convictions under the third category of JCE, the foreseeable crime) did in fact take place.[1] Where the principal perpetrator is not shown to belong to the JCE, the trier of fact must further establish that the crime can be imputed to at least one member of the joint criminal enterprise, and that this member – when using the principal perpetrator – acted in accordance with the common plan. In establishing these elements, the Chamber must, among other things: identify the plurality of persons belonging to the JCE (even if it is not necessary to identify by name each of the persons involved); specify the common criminal purpose in terms of both the criminal goal intended and its scope (for example, the temporal and geographic limits of this goal, and the general identities of the intended victims); make a finding that this criminal purpose is not merely the same, but also common to all of the persons acting together within a joint criminal enterprise;[2] and characterize the contribution of the accused in this common plan. On this last point, the Appeals Chamber observes that, although the contribution need not be necessary or substantial,[3] it should at least be a significant contribution to the crimes for which the accused is to be found responsible.[4]

Brđanin’s appeal was characterized by a large number of factual challenges. The Appeals Chamber identified eight categories of alleged errors which were summarily dismissed (paras 19-31):

(1)   Challenges to factual findings on which a conviction does not rely,

(2)   Arguments that misrepresent the Trial Chamber’s factual findings or the evidence, or that ignore other relevant factual findings made by the Trial Chamber,

(3)   Mere assertions that the Trial Chamber must have failed properly to consider relevant evidence,

(4)   Mere assertions that no reasonable Trial Chamber could have reached a particular conclusion by inferring it from circumstantial evidence,

(5)   Arguments that are clearly irrelevant or that lend support to the challenged finding,

(6)   Arguments that challenge a Trial Chamber’s reliance or failure to rely on one particular piece of evidence, disregarding the remaining evidence,

(7)   Arguments contrary to common sense, and

(8)   Challenges to factual findings where the relevance of the factual finding is unclear and has not been explained by the Appellant.

At para. 53, the Appeals Chamber recalled the applicable law when additional evidence is admitted on appeal, and specified that findings pertaining to mitigating circumstances are reached “on a balance of probabilities”:

53. In light of the above, the Appeals Chamber will now determine whether the Trial Chamber correctly assessed the evidence before it when evaluating the Appellant’s cooperation. The Appeals Chamber will then assess the value, if any, of the additional evidence admitted on appeal, and itself determine whether this material, when considered together with the materials before the Trial Chamber, warrants, on a balance of probabilities,[1] a finding of substantial cooperation and a reduction of sentence.

See also para. 8 and footnote 23.

The Appeals Chamber noted that, although cooperation with the Prosecution is the only mitigating factor referred to expressly in the Rules, “substantial cooperation” is not defined, and it is for the Trial Chamber to assess the extent and the nature of the accused’s cooperation. The Appeals Chamber considered that the assessment of whether or not the cooperation is “substantial” “primarily depends on the specific circumstances of each case and that substantial cooperation does not solely rest on one specific act of an accused but must be assessed as a whole”. The qualification of an accused’s cooperation as “substantial” will depend on the quantity and the quality of the information provided. See paragraph 51.

52. The Appeals Chamber stresses that the assessment of the quality of the provided information primarily depends on its “actual content”. In this regard, the provision of new information, “heard for the first time before this Tribunal”, has to be seen as particularly valuable. Special weight has previously also been given to the provision of unique and corroborative information to the Prosecution, as well as the identification of new crimes and perpetrators and of previously unknown mass graves. However, the content of the information is not the only criteria to be taken into account in the assessment of the quality of the information. Such quality […] will also depend on the earnestness of the accused in providing it.[2] […] Further, while the actual use by the Prosecution in other proceedings before the International Tribunal of information provided by an accused is not […] in itself proof of the quality of the submitted information, such use has to be seen […] as a significant indication of the value of this information.

On the earnestness of an accused’s cooperation, see also para. 63.

At para. 63, the Appeals Chamber also considered the determination within a plea agreement of any cooperation to be provided by an accused as significant indication of an accused’s willingness to cooperate with the Prosecution:

63. […] Although such specification is not mandatory, its inclusion is a significant indication of an accused’s willingness to cooperate with the Prosecution. It establishes clear obligations on the part of the accused, which can then be considered by a Trial Chamber when assessing the accused’s cooperation.

Bralo claimed that his cooperation went beyond mere cooperation with the Prosecution and argued that he actually cooperated “with the wider aims of the International Tribunal itself”. At para. 37, the Appeals Chamber found:

37. […] While the jurisprudence of the International Tribunal has consistently identified cooperation under Rule 101(B)(ii) of the Rules primarily as cooperation with the Prosecution,[1] cooperation is not to be “construed narrowly and singularly”,[2] and Trial Chambers accordingly have the discretion to take other forms of cooperation into account by examining them under different headings: what matters is that Trial Chambers fulfil their obligation under Rule 101(B)(ii) to consider all mitigating circumstances before them.[3]

27. […] The mens rea that attaches to contempt under Rule 77(ii) requires only knowledge of the facts that make the conduct of the accused illegal; that is, knowledge that the disclosure was in violation of an order of the Chamber. It is not a valid defence that one did not know that disclosure of the protected information in violation of an order of a Chamber was unlawful. As the Appeals Chamber has previously stated, where a person is subject to the International Tribunal’s authority, that person must abide by its orders “regardless of his personal view of the legality of those orders”.[1] Likewise, an accused may not raise a mistake of law as a defence to his knowing breach of an order of the International Tribunal on the ground that the mistake was founded on legal advice.