The Appeals Chamber restated in a concise manner the standard of review for admission of additional evidence (footnotes rearranged to have full names of decisions):

12. The admission of additional evidence on appeal is regulated under Rule 115 of the Rules. In order to be admissible pursuant to this Rule, the evidence put forward must satisfy a number of requirements. The applicant must first demonstrate that the additional evidence tendered on appeal was not available to him at trial in any form,[1] or discoverable through the exercise of due diligence.[2] The applicant’s duty to act with reasonable diligence includes making “appropriate use of all mechanisms of protection and compulsion available under the Statute and the Rules of the International Tribunal to bring evidence on behalf of an accused before the Trial Chamber.”[3]  He then must show that the evidence is both relevant to a material issue and credible, and that it could have had an impact on the verdict. In other words, the evidence must be such that, considered in the context of the evidence given at trial, it could demonstrate, in the case of a request by a defendant, that the conviction was unsafe.[4] A party seeking to admit additional evidence bears the burden of specifying with clarity the impact the additional evidence could have upon the Trial Chamber’s decision.[5]

13. If the evidence was available at trial, it may still be admissible on appeal if the applicant can meet the burden of establishing that exclusion of the evidence would lead to a miscarriage of justice, in that if it had been available at trial it would have affected the verdict.[6]

14. Whether the evidence was available at trial or not, the Appeals Chamber has repeatedly recognised that the evidence shall not be assessed in isolation, but in the context of the evidence given at the trial.[7]

The Appeals Chamber restated the applicable law with respect to the admissibility of the additional evidence on appeal:

5. Further, according to Rule 115 of the Rules of Procedure and Evidence of the Tribunal (“Rules”), for additional evidence to be admissible on appeal, the following requirements must be met. The Appeals Chamber must find “that the additional evidence was not available at trial and is relevant and credible.” When determining the availability at trial, the Appeals Chamber will be mindful of the following principles:

[T]he party in question must show that it sought to make “appropriate use of all mechanisms of protection and compulsion available under the Statute and the Rules of the International Tribunal to bring evidence […] before the Trial Chamber.” In this connection, Counsel is expected to apprise the Trial Chamber of all the difficulties he or she encounters in obtaining the evidence in question, including any problems of intimidation, and his or her inability to locate certain witnesses. The obligation to apprise the Trial Chamber constitutes not only a first step in exercising due diligence but also a means of self-protection in that non-cooperation of the prospective witness is recorded contemporaneously.[1]

With regard to relevance, the Appeals Chamber will consider whether the proposed evidence sought to be admitted relates to a material issue. As to credibility, the Appeals Chamber will admit evidence at this stage only if it appears to be reasonably capable of belief or reliance. Admission of the evidence is without prejudice to the later determination of the weight that the new evidence will be afforded.[2]

6. Once it has been determined that the additional evidence meets these conditions, the Appeals Chamber will determine whether the evidence “could have been a decisive factor in reaching the decision at trial.”[3] To satisfy this, the evidence must be such that it could have had an impact on the verdict, i.e. it, in the case of a request by a defendant, it could have shown that a conviction was unsafe.[4] Accordingly, the additional evidence must be directed at a specific finding of fact related to a conviction or to the sentence.

7. The Appeals Chamber has considered that, where the additional evidence is relevant and credible, but was available at trial, or could have been discovered through the exercise of due diligence, the evidence may still be admitted if the moving party establishes that its exclusion would amount to a miscarriage of justice, inasmuch as, had it been adduced at trial, it would have had an impact on the verdict.[5]

8. The Appeals Chamber recalls that, whether the additional evidence was available at trial or not, it must always be assessed in the context of the evidence presented at trial, and not in isolation.[6]

27. Subject to the limitations imposed by Rule 115, the Appeals Chamber may, in the same way as a Trial Chamber, admit evidence which is relevant and probative of the issues which it has to determine.[1]  Rule 115, however, limits the admissibility of such evidence in the Appeals Chamber where it relates to an issue or a fact litigated in the trial, and where it is additional to the evidence presented at the trial.  The Appeals Chamber will admit such additional evidence upon application by the party seeking to tender it where it was not available to that party at the trial by the exercise of reasonable diligence, and where the Appeals Chamber considers that the interests of justice require its admission in the appeal.  It is in the interests of justice to admit such evidence where it is relevant to a material issue, it is credible, and it is such that it would probably show that the conviction or sentence was unsafe (in the sense that, had the Trial Chamber had such evidence before it, it would probably have come to a different result).  The Appeals Chamber also has the inherent power to admit such evidence even when it was available at trial where its exclusion would lead to a miscarriage of justice.  The party seeking the admission of additional evidence carries the burden of persuasion in relation to these matters.[2]

The Appeals Chamber has clearly restated the applicable law on admissibility of additional evidence on appeal: 

4. The Appeals Chamber recalls that under the jurisprudence of the Tribunal and that of the International Criminal Tribunal for the Former Yugoslavia (“ICTY”), an appeal pursuant to Article 24 of the Statute of the Tribunal (Article 25 of the Statute of the ICTY) is not a trial de novo[1] and is not an opportunity for a party to remedy any “failures or oversights” made during the pre-trial and trial phases.[2] Rule 115 of the Rules of Procedure and Evidence of the Tribunal (“Rules”) provides for a mechanism to address “the situation where a party is in possession of material that was not before the court of first instance and which is additional evidence of a fact or issue litigated at trial”.[3]

5. According to Rule 115, for additional evidence to be admissible on appeal, the following requirements must be met: first, the motion to present additional evidence should be filed “not later than thirty days from the date for filing of the brief in reply, unless good cause or, after the appeal hearing, cogent reasons, are shown for a delay.[4] Second, the Appeals Chamber must find “that the additional evidence was not available at trial and is relevant and credible”.[5] When determining the availability at trial, the Appeals Chamber will consider whether the party tendering the evidence has shown that it sought to make “appropriate use of all mechanisms of protection and compulsion available under the Statute and the Rules of the International Tribunal to bring evidence […] before the Trial Chamber.”[6] In this respect, the Appeals Chamber has held that

Counsel is expected to apprise the Trial Chamber of all the difficulties he or she encounters in obtaining the evidence in question, including any problems of intimidation, and his or her inability to locate certain witnesses” and that “[t]he obligation to apprise the Trial Chamber constitutes not only a first step in exercising due diligence but also a means of self-protection in that non-cooperation of the prospective witness is recorded contemporaneously.[7]

With regards to relevance, the Appeals Chamber will consider whether the proposed evidence sought to be admitted relates to a material issue. As to credibility, the Appeals Chamber will only refuse to admit evidence at this stage if it does not appear to be reasonably capable of belief or reliance, without prejudice to a determination of the weight to be afforded.[8]

6. Once it has been determined that the additional evidence meets these conditions, the Appeals Chamber will determine whether the evidence “could have been a decisive factor in reaching the decision at trial.”[9] To satisfy this requirement, the evidence must be such that it could have had an impact on the verdict, i.e. it could have shown that a conviction was unsafe.[10] Accordingly, the additional evidence must be directed at a specific finding of fact related to a conviction or to the sentence.[11] Although Rule 115 of the Rules does not explicitly provide for this, where the evidence is relevant and credible, but was available at trial, or could have been discovered through the exercise of due diligence, the Appeals Chamber may still allow it to be admitted on appeal provided the moving party can establish that the exclusion of it would amount to a miscarriage of justice. That is, it must be demonstrated that had the additional evidence been adduced at trial, it would have had an impact on the verdict.[12]

7. The Appeals Chamber recalls that, whether the additional evidence was or was not available at trial, the additional evidence must always be assessed in the context of the evidence presented at trial, and not in isolation.[13]

CONSIDERING that, while Rule 115 of the Rules of Procedure and Evidence limits the extent to which evidence upon matters relating to the guilt or innocence of the accused may be given before the Appeals Chamber (being the issue litigated in the Trial Chamber), when the Appeals Chamber is hearing evidence which relates to matters other than the issues litigated in the Trial Chamber, the Appeals Chamber is in the same position as a Trial Chamber, so that Rule 107 applies to permit the Appeals Chamber to admit any relevant or probative evidence pursuant to Rule 89 (C) and, pursuant to Rule 90 (G), to exercise control over the mode of presenting evidence to avoid needless consumption of time;

68. [….] The Appeals Chamber does, however, take this opportunity to clarify that, in its view, the more appropriate standard for the admission of additional evidence under Rule 115[1] on appeal is whether that evidence “could” have had an impact on the verdict, rather than whether it “would probably” have done so. 

69. The Appeals Chamber considers this change from the earlier Tadić formulation  [Prosecutor v Duško Tadić, Case No. IT-94-1-A, “Decision on Appellant’s Motion for the Extension of the Time-Limit and Admission of Additional Evidence”, 15 October 1998, para. 71] as more a matter of timing than substance.  The “would probably” standard is still basically appropriate for the ultimate determination of whether a miscarriage of justice has occurred requiring a reversal.  The Appeals Chamber emphasises too that, regardless of the standard used, it is a difficult task to determine whether the interests of justice require the admission of new evidence.  The Appeals Chamber, therefore, expects a party seeking to admit evidence to specify clearly the impact the additional evidence could have upon the Trial Chamber’s decision.  If it fails to do so, it runs the risk of the evidence being rejected without detailed consideration.

6. [...] The admission of evidence is in the “interests of justice” if it is relevant to a material issue, if it is credible and it is such that it would probably show that the conviction or sentence was unsafe. The Appeals Chamber has interpreted this latter criterion to mean that had the Trial Chamber had such evidence before it, it probably would have come to a different result. This is the standard we have applied in our earlier decisions and which we will apply in this case.[1]

8. The Appeals Chamber further notes that Rule 115(B)’s insistence that admission of new material be “in the interests of justice” is one that the Appeals Chamber should apply at a relatively early stage of the Appeal, that is before all the briefs have been received and argument taken place. That means in practical terms that the Appeals Chamber must give its best judgement as to the importance of the new material in light of its familiarity with the trial record at that time. This means that even after a finding that the material has satisfied the requirements of Rule 115(B) the Chamber on further consideration and in the light of briefs and arguments may decide that indeed it is not so important that it would have changed the result and requires the overturning of the verdict or the alteration of a sentence. This of course is why the word “probably” is used in defining the test of Rule 115(B). This cautionary note is included because in argument it seemed to the Appeals Chamber that some counsel assumed that because we had already stated that the new material met the “interests of justice” test, it would ensure a reversal of the verdict, if admitted. That is not true. New material will be considered alongside the material already in the trial record to see if the Trial Chamber’s judgement is sustainable by the newly enlarged record on appeal and the usual deference will be given to a Trial Chamber’s findings of fact insofar as they were based on the material before the court at the time. The job of the Appeals Chamber is thus to decide in a simulation of sorts: given the findings of the trial court made on the evidence before it (and assuming that they pass muster for if they do not the case must be reversed or sent back in any case, regardless of the new evidence) would the Trial Chamber have probably come to a different conclusion if this new evidence had been before it.

13. The Appeals Chamber first notes that with respect to the standard for admission of evidence on appeal, Lazarević submits that two prerequisites must be met: (i) the material must have been unavailable at trial and (ii) its consideration by the Appeals Chamber must be in the interests of justice.[1] Had the material been available at trial, Lazarević argues that the Appeals Chamber retains the inherent power to consider it, if a failure to do so would result in a miscarriage of justice.[2] The Appeals Chamber finds that Lazarević misapprehends the standard for admission of additional evidence on appeal, as the “interests of justice” test reflects neither the current requirements of Rule 115(B) of the Rules nor the established jurisprudence of the Tribunal.[3] The Appeals Chamber will therefore examine Lazarević’s submissions in accordance with the correct standard articulated above.[4]

36.     Rule 115 (A) provides that a “party may apply by motion to present before the Appeals Chamber additional evidence which was not available to it at the trial”. That relates to appeals. Rule 119 enables a party to seek a review “[w]here a new fact has been discovered which was not known to the moving party at the time of the proceedings before a Trial Chamber or the Appeals Chamber, and could not have been discovered through the exercise of due diligence”. The Appellant submits that the reference to “diligence” in the latter but not in the former means that diligence is not required under Rule 115. However, whilst the Rules can illustrate the meaning of the Statute under which they are made, they cannot vary the Statute. If there is a variance, it is the Statute which prevails. But, for the reasons explained below, there is no variance in this case. In the view of the Appeals Chamber, there is a requirement for the exercise of due diligence by a party moving under Rule 115.

37.     Article 25, paragraph 1, of the Statute provides for appeals on two grounds, namely, “an error on a question of law invalidating the decision” and “an error of fact which has occasioned a miscarriage of justice”. The first error is clearly an error committed by the Trial Chamber. That, in principle, would seem to be also the case with the second error. But it is difficult to see how the Trial Chamber may be said to have committed an error of fact where the basis of the error lies in additional evidence which, through no fault of the Trial Chamber, was not presented to it. Where evidence was sought to be presented to the Trial Chamber but was wrongly excluded by it, there is no need for recourse to the provisions relating to the production of additional evidence to the Appeals Chamber; there the Trial Chamber would have committed an error appealable in the ordinary way.

38.     It is only by construing the reference to “an error of fact” as meaning objectively an incorrectness of fact disclosed by relevant material, whether or not erroneously excluded by the Trial Chamber, that additional material may be admitted. Such an extension of the concept of an “error of fact” as being not restricted to an error committed by the Trial Chamber may be required by justice; but justice would also require the accused to show why the additional evidence could not be presented to the Trial Chamber in exercise of the rights expressly given to him by the Statute. It would be right to hold that the purpose of the Statute in giving those rights was that the accused should exercise due diligence in utilising them. This would exclude cases in which the failure to exercise those rights was due to lack of diligence.

[…]

40.     The compulsory and protective machinery of the International Tribunal may not always be able to give total assurance that witnesses will be both available and protected if necessary. That is all the more reason why the machinery at the disposal of the International Tribunal should be used. A party seeking leave to present additional evidence should show that it has sought protection for witnesses from the Trial Chamber where appropriate, and that it has requested the Trial Chamber to utilise its powers to compel witnesses to testify if appropriate. Any difficulties, including those arising from intimidation or inability to locate witnesses, should be brought to the attention of the Trial Chamber.

[…]

42.     By the time proceedings have reached the Appeals Chamber, evidence relevant to the culpability of the accused has already been submitted to a Trial Chamber to enable it to reach a verdict and a sentence, if he is found guilty. From the judgement of the Trial Chamber there lies an appeal to the Appeals Chamber. The corrective nature of that procedure alone suggests that there is some limitation to any additional evidentiary material sought to be presented to the Appeals Chamber; otherwise, the unrestricted admission of such material would amount to a fresh trial. Further, additional evidence should not be admitted lightly at the appellate stage, considering that Rule 119 provides a remedy in circumstances in which new facts are discovered after the trial.

43.     Consideration may be given to the consequences of the opposite holding that additional evidence may be presented to the Appeals Chamber even where, through lack of diligence, it was not presented to the Trial Chamber though available. The Prosecutor can appeal from an acquittal. She may seek to reverse the acquittal on the basis of an error of fact disclosed by additional evidence. If the additional evidence was available to her but not presented to the Trial Chamber through lack of diligence, the accused is in effect being tried a second time. In substance, the non bis in idem prohibition is breached.

44.     The Appeals Chamber therefore finds that the position under the Statute is as indicated above and cannot be cut down by reference to any apparent discrepancy in the wording of Rules 115 and 119 of the Rules. The word “apparent” is used because, on a proper construction, Rule 115 is to be read in the light of the Statute; it is therefore subject to requirements of the Statute which have the effect of imposing a duty to be reasonably diligent. Where evidence is known to an accused person, but he fails through lack of diligence to secure it for the Trial Chamber to consider, he is of his own volition declining to make use of his entitlements under the Statute and of the machinery placed thereunder at his disposal; he certainly cannot complain of unfairness.

45.     In summary, additional evidence is not admissible under Rule 115 in the absence of a reasonable explanation as to why it was not available at trial. Such an explanation must include compliance with the requirement that the moving party exercised due diligence. This conclusion is consistent with the Statute and with the jurisprudence of many countries; it is not, however, dependent on that jurisprudence.

[…]

3.       Material which existed at trial but of which the Defence was unaware

[…]

58.     […] While the Defence is required to use due diligence to identify and seek out witnesses, there are limits to this obligation. The Appeals Chamber finds that the Appellant has provided sufficient indication that these witnesses and materials were unknown to the Defence, despite the exercise of due diligence, and thus not available at the time of trial […].

4.       Material which the Appellant was unable to adduce at trial

59.     This category relates to witnesses of whom the Defence was aware at the time of trial but whose evidence they were unable to produce. The material under this heading may be divided into three sub-categories: witnesses who were unwilling or unable to come forward at the trial stage, for example, witnesses who were imprisoned at the time; witnesses alleged to have been intimidated; and potential witnesses who could not be located at the time of trial.

60.     First, then, there is the category of potential witnesses who were simply unwilling to come forward at the trial stage but are now willing to do so at the appeal stage. […] No evidence has been submitted to the Appeals Chamber to indicate that any request was made to the Trial Chamber for the issue of subpoenas to compel the attendance of these witnesses. Despite the obvious practical difficulties in obtaining the evidence of such witnesses, a party cannot later seek to have such material admitted as additional evidence unavailable at trial unless it has raised the issue with the Trial Chamber at the time. As discussed above, the requirement of due diligence is not satisfied where there is insufficient attempt to invoke such coercive measures as were at the disposal of the International Tribunal. Therefore, it cannot be said that the evidence of these three witnesses was not available at trial.

[…]

62.     The second category is a substantial one. It relates to potential witnesses who were known to the Defence at the time of trial but who are said to have been intimidated by persons in authority in the former Yugoslavia. […] Again, in the absence of any evidence to demonstrate that attempts were made to obtain such protection for these witnesses as the International Tribunal could offer, the Appeals Chamber finds that reasonable diligence was not exercised. Consequently, the testimony of these witnesses cannot be said to have been unavailable at trial.

[RULE 115 OF THE ICTY RULES WAS SUBSEQUENTLY AMENDED ON 12 July 2002, 30 September 2002, and 21 July 2005]

66.     Also in this category are the 11 expert witnesses whom the Appellant would now like to call. […] Barring exceptional circumstances, which are not made out in this case, it is difficult to think of circumstances which would show that expert witnesses were not available to be called at trial despite the exercise of reasonable diligence. The evidence of these experts, and the related documents […], cannot be said to have been unavailable at trial for the purposes of Rule 115.

[RULE 115 OF THE ICTY RULES WAS SUBSEQUENTLY AMENDED ON 12 July 2002, 30 September 2002, and 21 July 2005]

52.     A preliminary matter of a general nature concerns the burden of proof. The question at issue in this Motion is whether the Appellant is entitled to a right given to him by the appeal process which he has invoked. It is for him to establish his entitlement to the right which he claims. Accordingly, it is for the Appellant to prove the elements of the entitlement.

53.     In the absence of any explanation as to why certain items now sought to be admitted were not available at trial, the Appeals Chamber finds that the Appellant has failed to discharge his burden of proof in respect of these items to its satisfaction. […]

G.      Interests of Justice

69.     As mentioned above, the Appeals Chamber finds that the following items were not available at trial within the meaning of Rule 115 (A): […] In relation to these items and […] the evidence of witness D.D., it will accordingly be necessary to consider the operation of the criteria relating to the interests of justice.

70.     If the Appeals Chamber at this stage authorises the presentation of additional evidence, it will be for the Chamber at a later stage to decide whether the evidence discloses an “error of fact which has occasioned a miscarriage of justice” within the meaning of Article 25, paragraph 1(b), of the Statute. At this stage, the Chamber cannot pre-empt this decision by definitively deciding that the proposed evidence does or does not disclose “an error of fact which has occasioned a miscarriage of justice”.

71.     The task of the Appeals Chamber at this stage is to apply the somewhat more flexible formula of Rule 115 of the Rules, which requires the Chamber to “authorise the presentation of such evidence if it considers that the interests of justice so require”. For the purposes of this case, the Chamber considers that the interests of justice require admission only if:

          (a) the evidence is relevant to a material issue;

          (b) the evidence is credible; and

          (c) the evidence is such that it would probably show that the conviction was unsafe.

72.     The Appeals Chamber would only add that, in applying these criteria, account has to be taken of the principle of finality of decisions. As mentioned above, the principle would not operate to prevent the admission of evidence that would assist in determining whether there could have been a miscarriage of justice. But clearly the principle does suggest a limit to the admissibility of additional evidence at the appellate stage.

73.     The Appeals Chamber also considers that, in applying these criteria, any doubt should be resolved in favour of the Appellant in accordance with the principle in dubio pro reo.

[RULE 115 OF THE ICTY RULES WAS SUBSEQUENTLY AMENDED ON 12 July 2002, 30 September 2002, and 21 July 2005]

With respect to the exercise of the applicant’s and counsel’s duty to act with due diligence in relation to the availability of evidence at trial, the Appeals Chamber recalled:

 5. For additional evidence to be admissible under Rule 115 of the Rules it must satisfy the following requirements. The applicant must first demonstrate that the additional evidence tendered on appeal was not available to him at trial in any form, or discoverable through the exercise of due diligence.[1] The applicant’s duty to act with reasonable diligence includes making “appropriate use of all mechanisms of protection and compulsion available under the Statute and the Rules of the International Tribunal to bring evidence on behalf of an accused before the Trial Chamber.”[2] With respect to the exercise of counsel’s due diligence during trial the Appeals Chamber recalls its finding in Tadić that

[c]ounsel may have chosen not to present the evidence at trial because of his litigation strategy or because of the view taken by him of the probative value of the evidence. The determination which the Chamber has to make, except in cases where there is evidence of gross negligence, is whether the evidence was available at the time of trial. Subject to that exception, counsel’s decision not to call evidence at trial does not serve to make it unavailable.[3]

The Applicant argued that a number of documents he sought to be admitted on appeal were not tendered into evidence at trial due to oversight by his former Counsel. When considering whether these documents were unavailable to the Applicant at trial, the Appeals Chamber first analysed documents which could demonstrate Counsel’s incompetence to conduct the defence:

12. With respect to the alleged unavailability at trial of the statements in document 69-K-0005, the Appeals Chamber recalls that a defence counsel has the duty to act with reasonable diligence to bring evidence on behalf of an accused before the Trial Chamber.[4] The information contained in the four statements could be considered as having been available at trial, because it could have been gathered with reasonable diligence.[5] However, failure of Counsel to exercise due diligence in order to obtain documents which could demonstrate his own incompetence to conduct the defence should not be to the detriment of the Appellant.[6] Moreover, whether or not the Appellant himself had a duty to act with reasonable diligence to make the Trial Chamber aware of the information contained in the four statements, the Appeals Chamber considers that in his oral request for self-representation at trial, the Appellant stated that his Defence team was unable to assist him because of the conditions prevailing at the time, adding that if the Trial Chamber wished that he provide more detailed explanations, he would gladly do so.[7] However, he was never requested to do so. In light of these circumstances, the Appeals Chamber finds that the information contained in the four statements was unavailable to the Appellant at trial. Consequently, they can be admitted if they are relevant, credible and could have had an impact on the verdict had they been considered at trial.

        […]

18. In addition, it appears that the Trial Chamber was never fully informed of the Appellant’s complaints regarding his former Counsel. […]

19. The Appeals Chamber considers that, as a general principle, an accused’s right to a fair trial is infringed when counsel admittedly does not understand the case of his client and fails to prepare a proper defence strategy. […]

 The Appeals Chamber then analysed the documents which were not aimed at proving the alleged incompetence of Counsel to conduct the defence:

21. As previously noted, the Appellant argues in relation to a number of documents that his former Counsel failed to tender them as evidence at trial, although for many of them the Appellant told him to do so.[8] The Appeals Chamber will only consider these documents as being unavailable at trial where the Appellant can show gross negligence of Counsel.[9]

22. The Appeals Chamber considers that […].it does not necessarily follow that former Counsel acted with gross negligence in all the respects now alleged. Indeed, “[c]ounsel may have chosen not to present the evidence at trial because of his litigation strategy or because of the view taken by him of the probative value of the evidence”.[10] Moreover, the Appellant does not substantiate his assertion that the documents at issue were unavailable at trial beyond bare assertions that former Counsel failed to tender them. Therefore, he fails to sufficiently demonstrate that these documents were unavailable at trial. As such, the other admissibility criteria being met, they will only be admitted if the Appellant can show that they would have affected the verdict.

Page 5:

 12. […] While there may be situations where a party may attempt to use Rule 142 of the Rules for the purpose of remedying tactical errors or oversights at trial, the Appeals Chamber considers that, in this instance, the heightened standard for admission sufficiently protects the interests of justice.