The Hala Protocol

5. Key Evidentiary Concepts in International Criminal Law

Audio data collected and processed by Collectors is ‘information’; information can become ‘evidence’ if used to establish facts in legal proceedings.1 The use of audio data as evidence has been seen in international criminal practice.2

Given the possibility of audio data being used as evidence in the future, this section identifies key evidentiary concepts that Collectors should keep in mind when collecting, handling, and preserving audio data. These concepts derive from the rules of evidence and case law of international criminal courts and tribunals international criminal courts and tribunals3 and have a broad applicability and recognition. To the extent that Collectors can incorporate these concepts into their work, it will improve the evidentiary value of their audio data.

Evidence is categorised differently depending on its nature. Audio data is considered a type of documentary evidence—a broad category that comprises ‘anything in which information of any description is recorded’.4 Some forms of audio data will be contemporaneous information, meaning that it was produced at the time that the events to be proven took place. Other forms of audio data will have been created after the relevant events. Examples of contemporaneous audio data are intercepted radio and phone communications; examples of non-contemporaneous audio data are recordings of witness interviews made after the events.

This section will first cover admissibility of evidence, clarifying what factors may (or may not) impact a court’s decision to admit an item of evidence at trial. It will then address the evidentiary concepts of relevance, probative value, reliability, authenticity, prejudicial effect, and weight of an item of evidence, assessing which elements make a piece of evidence more persuasive in proving an issue at trial. The section closes with information on the possibility of Collector team members being called as witnesses.

5.1 Admissibility of Evidence

For audio data to be relied upon as evidence in a criminal trial, it must first be admitted into evidence pursuant to the rules of procedure and evidence of the court. The paragraphs below set out core considerations relating to the admission of audio data as evidence.

A three-part test is used to determine the admissibility of an item of documentary evidence.5 The court must determine that:

  • The evidence is prima facie relevant (see section 5.2.);
  • The evidence has prima facie probative value (see section 5.3.); and
  • Where relevant, the prejudicial effect of the evidence does not outweigh its probative value (see section 5.4.).6

The admissibility of an item of evidence has no bearing on the final weight to be afforded to it (see section 5.5.).7 Generally, the international standards for admissibility are permissive8 and evidence is unlikely to be excluded.9

Despite this permissive standard, international criminal law does contain some exclusionary rules. The Rome Statute of the ICC establishes that evidence will not be admissible if

  1. it has been obtained in violation of the Statute or ‘internationally recognized human rights’; and
  2. the violation ‘casts substantial doubt on the reliability of the evidence’ (the concept of reliability is dealt with in section 5.3.), or the admission of the evidence ‘would be antithetical to and would seriously damage the integrity of the proceedings’.10

A and B are cumulative requirements, and the threshold for B is relatively high. For example, the failure of domestic authorities to comply with domestic procedural law when collecting evidence would not, in and of itself, be enough to damage the integrity of ICC proceedings (even in a situation where this breach of domestic law resulted in a violation of the right to privacy).11 A classic example of evidence being both unreliable and antithetical to the integrity of proceedings, and thus meeting the said threshold, would be a confession obtained through torture.

Other international criminal courts and tribunals international criminal courts and tribunals have exclusionary rules similar to those of the ICC,12 and the threshold for exclusion has been similarly high. When it comes to phone intercepts, case law from other courts and tribunals shows that intercepts obtained illegally per domestic law will not necessarily be inadmissible.13 Rather, case law suggests that the manner and circumstances in which they were obtained, as well as their reliability and effect on the integrity of the proceedings, will be factored into the assessment of their admissibility.14 The case law has further underscored that, in situations of armed conflict in particular, intelligence that may result from illegal activity may prove essential in uncovering the truth, especially when this information is not available from other sources.15 Intercepts have been generally admitted unless the integrity of the proceedings would be seriously damaged.16

With regard specifically to data that has been hacked and then leaked, there is no rule that such data would be per se inadmissible. Hacked data is data ‘acquired by an outsider who gains unauthorised access to it’, and leaked data is understood as data ‘obtained by an insider who has authorised access to it, but shares it in an unauthorised manner’.17 Hacked or leaked data may be inadmissible if its authenticity cannot be established18 or if the above exclusionary rule applies.19

In addition to sharing audio data with international courts and tribunals, Collectors may intend to transfer collected audio data to domestic authorities. In the latter case, Collectors should examine the admissibility requirements applicable in that particular jurisdiction.

5.2 Relevance of Evidence

An item of evidence is relevant when it pertains to the matters considered at trial. In other words, when it can be used to show that the existence of a particular fact is more or less probable. If evidence is irrelevant, it can be ruled inadmissible; or, if it has low relevance, it will likely be ascribed less weight by the judges.

Audio data will likely be considered relevant by international criminal courts and tribunals if it constitutes a contemporaneous, chronological record of events on the ground relevant to the charges.20 If a member of the Collector’s team involved in the collection process can testify to the fact that the recordings are a contemporaneous record (through her or his personal recollection, the metadata, and other documentation, etc.), this will contribute positively to a finding that the audio data is relevant to the case at hand.21 Accurate documentation of the date on which the audio data was collected is key to the data’s relevance, as this is necessary to show that the data relates to the period of time the criminal charges are concerned with.22 Likewise, information as to the location where the audio data was recorded will be important for relevance.23

When it comes to determining relevance, intelligibility is fundamental. This means that the relevant material should be presented in an understandable format (readable and/or audible). For example, raw or non-demodulated radio signals would be considered unintelligible and, thus, may be deemed inadmissible.24 Moreover, the material can be reviewed for relevance only if it is presented in one of the working languages of the relevant court, meaning that translations are fundamental and translated transcripts will likely be required.25 Collectors should bear in mind that the use of professional translators may be needed to support automated translations. Where only the ambient sound of the audio data is relevant (and not human voices) it is possible that transcription will not be necessary.26

Logbooks (in a working language of the relevant court) have also been reviewed by courts and considered ‘an essential part of the […] assessment of particular recordings’ as they were deemed ‘contemporaneous written records’ of the intercepted communications.27 Collectors should thus be ready to provide transcripts and translations of the audio recordings as well as their contemporaneous documentation of the recording process in an intelligible manner. While desirable, it may not always be necessary for the court to have access to the original audio recordings when enough evidence surrounding the audio data (e.g., corroborative testimonial evidence and large amounts of documentary evidence) exists.28

Case law demonstrates that relevance is not necessarily affected by minor time and date discrepancies29 or by disagreements between the parties as to how to interpret what is said in an audio recording.30 Possible discrepancies between the original and the translated versions of the audio recording are also not an obstacle to their relevance per se.31 These issues contribute to the weight of the evidence, rather than the relevance. Collectors should therefore not discount audio data on these bases.

5.3 Probative Value of Evidence

An item of evidence is probative when it has the potential to prove or disprove an asserted fact. Probative value is not synonymous with relevance, although the two are sometimes confused.32 Relevance is a ‘yes or no’ question, while probative value is more of a spectrum: a relevant item of evidence can have lower or higher probative value.

An assessment of the probative value of a piece of evidence is seldom based on a single factor. The following have been considered in the ICL case law as enhancing the probative value of audio data: a) where it was collected from;33 b) the provision of the original audio recording to the court alongside transcripts and translations; c) the fact that a voice on an audio recording has been identified as the defendant; and d) the confirmation of the information in the audio recording by a witness.34 The probative value of audio evidence can also be bolstered by additional information that can, for example, help to identify the voice that is heard in the recording, or establish the circumstances of the audio recording’s creation, preservation, and handling.35

Advanced technological capacity and professional expertise are not required to provide probative value to audio data.36 That said, for the data to have higher probative value, it may have to be shown that the person who obtained/collected it had the technical means to do so.37 Collectors should therefore ensure that team members involved in audio data collection are adequately trained and keep up to date with the latest technological developments.

Information regarding the provenance of audio data is particularly important in determining its probative value. Provenance ‘relates to the origin or earliest known existence of something’.38 For audio data, provenance can mean different things depending on the data source. For intercepted communications, the actor making the audio recording of the communication will be the creator–or the author–of the data. Collectors engaged in interception can therefore speak to the provenance of the resulting audio data. The same is true for situations where a Collector is recording an interview with a witness or a live radio broadcast. By contrast, when Collectors are engaged in open-source data collection, for example from social media sites, or when an audio recording is sent to them over an instant messaging app, the author of the data is a third party. Additional steps will therefore be needed to establish and adequately record details of the data’s provenance. For content posted to social media, information such as the uploader, the page to which material was posted, and the post title and description can help to establish provenance, which speaks to reliability and authenticity, and by extension, probative value.39

Being unable to provide information about audio data’s provenance, or providing only limited information, will negatively impact its probative value, in some cases to the extent that the data will be inadmissible.40 Ideally, the author of the data would testify in court with the data being submitted into evidence through them as a witness; this will improve the probative value of data by allowing for the scrutiny of cross examination.41 While there is no blanket prohibition on admitting evidence where its purported author has not been called to testify, factors such as ‘proof of authorship will naturally assume the greatest importance’ in judges’ determination of the weight of evidence.42 Weight, as is detailed below in section 5.5., is the relative importance attached to an item of evidence in deciding whether a certain issue has been proven or not.43

Reliability of evidence as an element of probative value

Reliability is an important part of the admissibility test as it is necessary for probative value. Unreliable evidence will not be admissible. An item of evidence is considered reliable if the veracity and accuracy of its content can be trusted. Accordingly, an item of evidence is deemed insufficiently reliable if it cannot be said to prove or disprove a relevant assertion.44

Different factors are relevant when assessing reliability. It must be ascertained whether the evidence displays such qualities that, when considered alone, could reasonably be believed.45 The case law has held that ‘there is no finite list of possible criteria that are to be applied in determining reliability.’46 The following factors are important in the assessment of items of evidence:

  1. the source of the information, in particular whether the source has an allegiance towards one of the parties in the case or has a personal interest in the outcome of the case, or whether there are other indicators of bias;
  2. the nature and characteristics of the item of evidence (e.g., whether the evidence is an audio or video recording, the public or private character of the information, etc.);
  3. the contemporaneous nature of the evidence (i.e. whether the information was obtained and recorded simultaneously or shortly after the events to which it pertains);
  4. the purpose of the item (whether the document was created for the specific purpose of criminal proceedings or for some other reason); and
  5. adequate means of evaluation (whether the information and the way in which it was gathered can be independently verified or tested).47

Consistency, clarity, and transparency in the collection process are crucial factors for the reliability of audio data.48 Collectors must therefore ensure that their collection processes are documented in great detail49 and applied consistently, with changes to the documentation process explained where needed. Maintaining a detailed record can help to overcome any evidentiary shortcomings that may arise throughout the collection process.50

Careful recordkeeping helps to establish chain of custody, which in turn is important to proving reliability. Chain of custody ‘refers to the chronological documentation of the sequence of custodians of a piece of information or evidence, and documentation of the control, date and time, transfer, analysis and disposition of any such evidence’.51 An imperfect chain of custody does not necessarily render the data inadmissible, but the chain of custody concerns will factor into the reliability and probative value assessment.52

Where the author of the data is the Collector—for example, where it is the Collector who has made the audio recording—demonstrating chain of custody is reasonably straightforward. It involves keeping a careful record of who had access to the data and of any time the data was accessed, moved, transferred, or in any way altered or copied. Where the Collector is not the author, efforts should be made to document the data’s chain of custody before it was collected by the Collector. Where audio data has been transferred to the Collector by an official source, such as law enforcement authorities, securing an official document confirming chain of custody will help to establish reliability.53 Alternatively, identifying witnesses who can speak to the provenance and chain of custody of the audio data will be helpful,54 as will witness testimony identifying the voices on the audio recording.55

Detailed record keeping is also of particular importance when audio data is subject to enhancement. Enhancement aims to improve ‘the quality of the original audio material to enable members of the court to comprehend or interpret the material to the best possible standard without adding to or detracting from the content of the original’.56 The following factors have been found to improve the reliability of enhanced audio data:

  1. enhancements made on a duplicate of the audio data, keeping the original preserved for comparison purposes;
  2. corresponding labels on the original and the enhanced copy;
  3. corresponding track times on the files;
  4. broadly corresponding contents between the original and the enhanced copy when compared side by side; and
  5. submission of a technical report describing the exact processes applied to each piece of data.57

In addition to the above, reliability is boosted when two or more team members have collected the same audio data, with only slight or no variations from each other.58 This particularly applies when team members work from different locations,59 or when the communication is recorded by listening devices in different locations. When multiple logbooks for a particular communication exist (for example, because the same audio data was collected from different locations), a ‘word-for-word mirroring’ is not expected for corroborative effect. Instead, ‘differences in details are to be expected’—considering possible differences in the levels of experience of the intercepting personnel, the potential for varying quality of what could be heard at the interception site, and the fact that different people will inevitably summarise long conversations in different ways and focus on different parts.60 Discrepancies in the logs do not necessarily require them to be corroborated by the transcripts of the audio recordings or testimony of the intercept personnel, nor do such discrepancies render the logbooks unreliable.61

Logs are not viewed as ‘verbatim transcripts’ of the audio recordings and are generally considered together with transcripts, witness testimonies, and other logbooks to verify the conversations’ accuracy and the meaning.62

Reliability can be improved by other kinds of corroborating evidence, such as the testimony of the team members who collected and worked with the audio files.63 As noted in section 5.6., team members should be prepared to be called as witnesses to explain the Collector’s processes. Non-witness evidence is also significant for improving reliability through corroboration: documents, reports, aerial images, and photographs have all played a corroborating role in the case law.64 Corroborating evidence can help to overcome reliability challenges that arise from uncertainties in the chain of custody. For example, if a digital file’s metadata indicates the data may have been accessed by a third party or external software, this does not per se mean that the audio itself has been modified; rather, in such a case, witness evidence and other corroborating evidence will be needed to support the data’s reliability.65

Finally, Collectors should bear in mind that their impartiality (or lack thereof) is relevant to an assessment of reliability.66 Without sufficient guarantees of ‘non-partisanship and impartiality’, information collected by NGOs may not be deemed prima facie reliable and might not be admissible.67

Authenticity of evidence as an element of reliability

Authenticity relates to whether a piece of evidence is what it professes to be in origin or authorship.68 Authenticity is an important indicator of reliability. Several factors may be considered when assessing authenticity. Relevant considerations include whether there is verifiable information regarding the source, evidence of originality and integrity of the content,69 and a preserved and documented chain of custody. Information about the date and the author have also been considered important.70

Witness testimony is crucial for establishing authenticity. The relevant Collector team members should, therefore, be prepared to be called to testify—for example, to confirm that they recognise the recording and associated transcripts and to confirm that it is the same recording as the one they were involved in collecting.71 In addition, an individual’s self-identification during the intercepted communication can serve as an inherent indicator of the communication’s authenticity.72

Certain factors that contribute to the reliability of evidence can also contribute to its authenticity. In relation to audio data, authenticity can be enhanced by other independent corroborative evidence, such as recordings made by others of the same conversations or other documentary evidence.73

5.4 Prejudicial Effect of Evidence

Under the third and last step of the admissibility test, the court must, where relevant, balance the probative value of the item of evidence under consideration against any prejudicial effect that its admission may cause to the fairness of the proceedings as a whole, and in particular, to the rights of the accused. The item will be excluded if its relevance and probative value are insufficient (or insufficiently substantiated74) to justify its admission in light of its potentially prejudicial effect.75

This balancing exercise is to be done on a case-by-case basis. For example, evidence of prior criminal or immoral conduct may suggest that the defendant is of bad character or prone to commit a crime; if the conduct in question is not strictly related to the charges, the probative value of such evidence may not justify the admission of the evidence because of its prejudice to the defendant’s fair trial rights.

5.5 Weight of Evidence

Weight is a similar but distinct concept from probative value. It is the relative importance attached to an item of evidence in deciding whether a particular issue has been proven or not.76 When determining weight, items of evidence are weighed against each other.77 Judges usually determine the final weight to be accorded to the evidence when assessing the evidence as a whole at the end of the case.78

5.6 Collector Personnel Serving as Witnesses in Criminal Proceedings

It is preferable, where possible, for audio data to be submitted into evidence through a witness.79 Operators involved in collecting audio data, their supervisors, and prosecution office staff are often called as witnesses to testify in court about the collection operations and specific communications.80 In the ICC system, among others, witness testimony can also be introduced through prior recorded statements.81

Not all persons involved in data collection operations need to testify at trial.82 Nevertheless, Collector team members should be prepared to testify as witnesses (or, if applicable and appropriate, to provide prior recorded statements) regarding their collection and processing activity. Collector personnel may be called to testify before one or more different accountability mechanisms.

Determining which individual is best suited to provide evidence will depend on various factors, including individuals’ respective roles in the collection process and degrees of expertise. Testimony will likely focus less on the content of the communication collected and more on the process of collection, processing, storing, and so on to establish the reliability of the audio data.

Where there are concerns for the safety and well-being of witnesses, courts can order protective measures, including

  • Face/voice distortion while the witness is giving evidence;
  • Use of a pseudonym;
  • Conducting parts of hearings in private or closed sessions; and
  • Prohibiting the Prosecution, the Defence, and any other participant in the proceedings from disclosing identifying information to a third party.

Footnotes

  1. OHCHR, Berkeley Protocol, page 7. ↩

  2. See, most recently, Prosecutor v Ongwen, Appeal Judgment, ICC-02/04-01/15-2022-Red, 15 December 2022 (Prosecutor v Ongwen, Appeal Judgment) and Prosecutor v Al-Hassan, Judgment, ICC-01/12-01/18-2594-Red, 26 June 2024 (Prosecutor v Al-Hassan, Judgment). ↩

  3. When working with a particular domestic jurisdiction, there may be additional and possibly more stringent evidentiary standards to consider and comply with. ↩

  4. Prosecutor v. Musema, Judgment and Sentence, ICTR-96-13-T, 27 January 2000, para. 53. ↩

  5. See, for example, Prosecutor v Lubanga, Corrigendum to Decision on the admissibility of four documents, ICC-01/04-01/06, 20 January 2011, paras. 28–31; Prosecutor v Bemba, Public redacted version of the First decision on the prosecution and defence requests for the admission of evidence, dated 15 December 2011, ICC-01/05-01/08-2012-Red, 9 February 2012, para. 13. ↩

  6. See, for example, Prosecutor v Lubanga, Corrigendum to Decision on the admissibility of four documents, ICC-01/04-01/06, 20 January 2011, paras. 28–31; Prosecutor v Bemba, Public redacted version of the First decision on the prosecution and defence requests for the admission of evidence, dated 15 December 2011, ICC-01/05-01/08-2012-Red, 9 February 2012, para. 13. ↩

  7. Prosecutor v Bemba, Decision on the admission into evidence of items deferred in the Chamber’s “Decision on the Prosecution’s Application for Admission of Materials into Evidence Pursuant to Article 64(9) of the Rome Statute” (ICC-01/05-01/08-2299), ICC-01/05-01/08, 27 June 2013 (Prosecutor v Bemba, Decision on the admission into evidence of deferred items), para. 9. ↩

  8. The ICTY and ICTR legal frameworks establish that chambers ‘may admit any relevant evidence which it deems to have probative value’ (ICTY RPE, Rule 89(C); ICTR RPE, Rule 89(C)). The ICC framework provides that judges freely assess all types of evidence submitted, enjoying in this respect ‘a significant degree of discretion’ (ICC RPE, Rule 63(2)); See, inter alia, Prosecutor v Lubanga, Decision on the admissibility of four documents, ICC-01/04-01/06, 13 June 2008, para. 24. ↩

  9. See Diletta Marchesi, ‘Intercepted Communications in the Ongwen Case: Lessons to Learn on Documentary Evidence at the ICC’ (2021) 22 International Criminal Law Review 1 page 8 (‘the admissibility standard for documentary evidence is not only ‘permissive’, but almost absent.’);Yvonne McDermott, Proving International Crimes (OUP 2024) page 64 (‘Trial Chambers have taken an inclusive approach to the admissibility of evidence, with any weaknesses in the evidence more likely to speak to its ultimate weight than to its probative value for the purposes of admissibility’); Nikita Mehandru and Alexa Koenig, ‘Open Source Evidence and the International Criminal Court’ (2019) Harvard Human Rights Journal (‘While information will often be admitted as evidence if shown to be even remotely relevant, the weight that judges will accord that information may vary.’) ↩

  10. Rome Statute, Article 69(7). ↩

  11. See Prosecutor v Bemba et al, Decision on Request in Response to Two Austrian Decisions, ICC-01/05-01/13-1948, 14 July 2016. See also Prosecutor v Bemba et al, Decision on Requests to Exclude Western Union Documents and other Evidence Pursuant to Article 69(7), ICC-01/05-01/13-1854, 29 April 2016 and Prosecutor v Bemba et al, Appeal Judgment, para. 289. See further Petra Viebig, Illicitly Obtained Evidence at the International Criminal Court (TMC Asser Press, 2016) pages 147-149. ↩

  12. ICTY RPE, Rule 96; ICTR RPE, Rule 95; STL RPE, Article 162; RMICT RPE, Rule 117; Kosovo Specialist Chambers (KSC) RPE, Rule 138. ↩

  13. In Prosecutor v Renzaho, Decision on Exclusion of Testimony and Admission of Exhibit, paras. 15–16, the ICTR held that the tape of a call between Rwandan authorities which was intercepted by Rwandan Patriotic Front soldiers using a walkie-talkie and simultaneously recorded by a journalist was not ‘antithetical to and certainly would not seriously damage the integrity of the proceedings’. In Prosecutor v Brdjanin, Decision on the Defence “Objection to Intercept Evidence”, paras. 53-5, the ICTY underlined that its jurisprudence had never upheld the exclusionary rule as a matter of principle: the right to privacy can be derogated from in times of emergency as in the course of a war, hence ‘communications intercepted during an armed conflict are not as such subject to exclusion under Rule 95 and should therefore be admitted’. In Prosecutor v Mbarushimana, Decision on the confirmation of charges, ICC-01/04-01/10-465-Red, 16 December 2011, para. 71, the ICC rejected a Defence challenge to the admissibility of intercepted phone calls, in part, because the Defence had failed to make ‘any submissions to the effect that a lack of authorisation of the intercepts would have any impact on the reliability of the evidence thereby obtained, or that their admission into evidence would be antithetical to or would seriously damage the integrity of the proceedings’. ↩

  14. Prosecutor v Brdjanin, Decision on the Defence “Objection to Intercept Evidence”, para. 55. ↩

  15. Prosecutor v Brdjanin, Decision on the Defence “Objection to Intercept Evidence”, para. 61; Prosecutor v. Kordić and Čerkez, Public Transcript of Hearing 2 February 2000, ICTY Case No. IT-95-14/2, 2 February 2000, page 13694. See also M. Klamberg, Evidence in International Criminal Trials, Confronting Legal Gaps and the Reconstruction of Disputed Events (Martinus Nijhoff, 2013), pages 395-406. ↩

  16. Prosecutor v Brdjanin, Decision on the Defence “Objection to Intercept Evidence”, paras. 61 and 63. ↩

  17. Lindsay Freeman, ‘Hacked and Leaked: Legal Issues Arising From the Use of Unlawfully Obtained Digital Evidence in International Criminal Cases’ (2021) 25(2) UCLA Journal of International Law and Foreign Affairs 45 (Freeman, Hacked and Leaked), page 47. ↩

  18. As was the case in The Prosecutor v. Ayyash, Badreddine, Merhi, Oneissi, and Sabra, Decision on the Admissibility of Documents Published on the Wikileaks Website, STL-11-01/T/TC/F1955/20150521/R274176-R274189/EN/af, 21 May 2015, paras 40-43. ↩

  19. See Rome Statute, Article 69(7). For a detailed discussion on when hacked and leaked data may be inadmissible on these (and other) grounds, see generally Freeman, Hacked and Leaked. ↩

  20. Prosecutor v Mladić, Decision on Prosecution’s Bar Table Motion for the Admission of Intercepts: Srebrenica Segment, IT-09-92, 2 May 2013, (Prosecutor v Mladić, Decision on Admission of Intercepts), para. 24. ↩

  21. Prosecutor v Popović et al., Judgment Volume I, ICTY, Case No. IT-05-88-T, 10 June 2010 (Prosecutor v Popović, Judgment), para. 65. ↩

  22. Prosecutor v Ntaganda, Decision on Prosecution’s request for admission of documentary evidence, ICC-01/04-02/06-1838, 28 March 2017, para. 68; Prosecutor v. Bemba, Public Redacted Version of “Decision on the Prosecution’s Application for Admission of Materials into Evidence Pursuant to Article 64(9) of the Rome Statute” of 6 September 2012, ICC-01/05-01/08-2299-Red, 8 October 2012 (Prosecutor v. Bemba, Public Redacted Version of “Decision on Admission of Materials”), para. 84; Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 24. ↩

  23. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 24. ↩

  24. This can be inferred by analogy from the case law of international criminal courts and tribunals concerning call data records—a form of metadata that provides information about the communication, including source, date, time and duration of the call. Call data records have been considered inadmissible on the basis of their unintelligibility. See Prosecution v Ayyash et al., Judgment, STL-11-01/T/TC, 18 August 2020, paras. 375–378, where the Trial Chamber rejected the admission of call data records due to it being voluminous and unreadable and containing a string of numbers and symbols. See also, Leiden Guidelines on the Use of Digitally Derived Evidence in International Criminal Courts and Tribunals (Leiden Guidelines), Guideline E1 on call data records. ↩

  25. Prosecutor v Ongwen, Trial Judgment, ICC-02/04-01/15-1762-Red, 4 February 2021 (Prosecutor v Ongwen, Trial Judgment), paras. 648, 650. ↩

  26. Prosecutor v Mladić, Transcript, IT-09-92 (19 September 2012), page 2634. ↩

  27. Prosecutor v Ongwen, Trial Judgment, para. 658. ↩

  28. Prosecutor v Blagojević and Jokić, Decision on Admission into Evidence of Intercept-Related Materials, ICTY, Case No. IT-02-60-T, 18 December 2003 (Prosecutor v Blagojević and Jokić, Decision on Admission of Intercept-Related Materials), para. 25. ↩

  29. Prosecutor v. Mladić, Decision on Prosecution Motion to Admit Evidence from the Bar Table: Excerpts from Mladic’s Audio Tapes, ICTY, Case No. IT-09-92-T, 18 September 2013, (Prosecutor v Mladić, Decision on Excerpts from Mladic’s Audio Tapes), para. 8. ↩

  30. ​​ ​​Prosecutor v Mladić, Decision on Excerpts from Mladic’s Audio Tapes, para. 9. ↩

  31. Prosecutor v. Popović et al., Decision on Admissibility of Intercepted Communications, ICTY, Case No. IT-05-88-T, 7 December 2007, paras. 75 and 78. ↩

  32. See, e.g., Prosecutor v. Bemba, Decision Pursuant to Article 61(7)(a) and (b) of the Rome Statute on the Charges of the Prosecutor against Jean-Pierre Bemba Gombo, ICC-01/05-01/08, 15 June 2009, para. 42, where it states that an item of evidence is considered relevant if it has probative value. ↩

  33. Their probative value was justified by the fact that they had been recovered by the Serbian authorities from the residence of the defendant’s family (Prosecutor v Mladić, Decision on Excerpts from Mladic’s Audio Tapes, para. 9). ↩

  34. Prosecutor v. Mladić, Decision on Prosecution Motion for Admission of Documents from the Bar Table, paras. 11-12. ↩

  35. Leiden Guidelines, Guideline F4, citing Prosecutor v. Bemba, Public Redacted Version of “Decision on Admission of Materials”, paras. 84, 119, and 121. ↩

  36. Prosecutor v Mladić, Judgment Volume IV of V, IT-09-92-T, 22 November 2017, paras. 5305-5307; Prosecutor v. Mladić, Transcript, IT-09-92, 13 August 2015, pp. 37746–37747. ↩

  37. Leiden Guidelines, Guideline D5. The Trial Chamber in Prosecutor v Blagojević and Jokić, Decision on Admission of Intercept-Related Materials noted the experience of the interceptors, their professional certifications, and how long standing their experience in the conflict was (para. 22). The Chamber in Prosecutor v Ongwen, Trial Judgment also noted the qualification of the witnesses, namely that they were either the intercept operators or their supervisors (multiple paragraphs). ↩

  38. OHCHR, Berkeley Protocol, page 63. ↩

  39. Prosecutor v Al-Hassan, Judgment, para. 726 fn. 2175. ↩

  40. Prosecutor v Renzaho, Decision on Exclusion of Testimony and Admission of Exhibit, para 1. ↩

  41. Prosecutor v Delalic, Decision on the Motion of the Prosecution for the Admissibility of Evidence, ICTY Case No. IT-96-21, 19 January 1998 (Prosecutor v Delalic, Decision on Admissibility of Evidence), para 22. ↩

  42. Prosecutor v Delalic, Decision on Admissibility of Evidence, paras 20-22, cited with approval in Prosecutor v Brdjanin and Talić, Order on the Standards Governing the Admission of Evidence, ICTY Case No. IT-99-36-T, 15 February 2002, para 18. ↩

  43. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, paras. 13-14. ↩

  44. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 28. ↩

  45. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 26. ↩

  46. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 27. ↩

  47. See Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 27. ↩

  48. Prosecutor v Tolimir, Judgment, ICTY Case No. IT-05-88/2-T, 12 December 2012 (Prosecutor v Tolomir, Judgment), para. 64, referring to Prosecutor v Tolimir, Transcript, ICTY, Case No, IT-05-88/2-T, 7 September 2010, p. 5033; Prosecutor v Blagojević and Jokić, Decision on Admission of Intercept Materials, para. 21. See also Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para 30 where, in relation to reports composed by NGOs, the Chamber stressed the importance of providing information on ‘their sources and the methodology used to compile and analyse the evidence upon which the factual assertions are based’. Without this information, the Chamber ‘cannot assess the reliability of the content of the reports’. ↩

  49. Prosecutor v Ongwen, Decision on the confirmation of charges against Dominic Ongwen, ICC-02/04-01/15-422-Red, 23 March 2016 (Prosecutor v Ongwen, Confirmation of Charges), para. 51; the Berkeley Protocol furthermore provides that ‘[i]nvestigators should document their activities during each phase. This will help with the understandability and transparency of their investigations, including chains of custody, and with the efficiency and efficacy of their investigations, including completeness and communication among team members’ (OHCHR, Berkeley Protocol, page 53). ↩

  50. Prosecutor v Ongwen, Confirmation of Charges, para. 51; Prosecutor v Ongwen, Transcript, ICC-02/04-01/15-T-20-Red-ENG, 21 January 2016, para. 44, lines 8-24. ↩

  51. OHCHR, Berkeley Protocol, page 61. ↩

  52. Prosecutor v Brdjanin, Judgement, ICTY Case No. IT-99-36-T, 1 September 2004 (Prosecutor v Brdjanin, Judgement), para 34. In this case, what made the chain of custody less than perfect was the fact that they were stored in the unsupervised possession of a person for more than 10 years before being transferred to the ICTY. ↩

  53. Prosecutor v Ngirabatware, Decision on the Third Defence Motion for Admission of Documentary Evidence, ICTR Case No. ICTR-99-54-T, 4 July 2012, para 46. For further background on this example, see Prosecutor v Ngirabatware, Defence Reply to Prosecution Response to Defence Motion for Admission of Documentary Evidence, ICTR Case No. ICTR-99-54-T, 14 March 2012, paras 23-29. ↩

  54. Prosecutor v Popović, Judgment, paras 64-65 ↩

  55. Prosecutor v Brdjanin, Judgment, para 34. ↩

  56. Prosecutor v Ongwen, Trial Judgment, para. 651. ↩

  57. Prosecutor v Ongwen, Trial Judgment, paras. 654-655. ↩

  58. Prosecutor v Krstić, Judgment, ICTY, Case No. IT-98-33-T, 2 August 2001 (Prosecutor v Krstić, Judgment), para. 108; Prosecutor v Blagojević and Jokić, Decision on Admission of Intercept Materials, paras. 24 and 26. ↩

  59. Prosecutor v Krstić, Judgment, para. 108; Prosecutor v Blagojević and Jokić, Decision on Admission of Intercept-Related Materials, paras. 24 and 26. ↩

  60. Prosecutor v Ongwen, Trial Judgment, para. 664. ↩

  61. Prosecutor v Ongwen, Appeal Judgment, para. 593. ↩

  62. Prosecutor v Ongwen, Appeal Judgment, para 597; Prosecutor v Ongwen, Trial Judgment, para. 558. ↩

  63. Prosecutor v Ongwen, Confirmation of Charges, para. 51; Prosecutor v Ongwen, Trial Judgment, para. 643. ↩

  64. Prosecutor v Krstić, Judgment, paras. 114-116; Prosecutor v Blagojević and Jokić, Decision on Admission of Intercept Materials, para. 24. ↩

  65. Prosecutor v Al-Hassan, Judgment, para. 811 fn. 2572. ↩

  66. The ICC’s Trial Chamber II, when deciding on the admissibility of two UN reports, considered it relevant to a determination of probative value that the reports were ‘established by UN services acting in an impartial manner with a concern to understand the events in question’ (Prosecutor v Katanga and Ngudjolo, Transcript, ICC-01/04-01/07-T-229-Red-ENG, 7 December 2010, page 24). ↩

  67. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para 30, cited with approval in Prosecutor v. Bemba, Public Redacted Version of “Decision on Admission of Materials”, para 35, which in turn was cited with approval in Prosecutor v Bemba, Judgment pursuant to Article 74 of the Statue, ICC-01/05-01/08-3343, 21 March 2016 (Prosecutor v. Bemba, Judgment), para 270. ↩

  68. Prosecutor v Prlić et al, Decision on Jadranko Prlić’s Interlocutory Appeal against the Decision on Prlić Defence Motion for Reconsideration of the Decision on Admission of Documentary Evidence, ICTY Case No. IT-04-74-AR73.l6, 3 November 2009, para. 34. ↩

  69. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, para. 24. ↩

  70. Leiden Guidelines, Guideline F4. ↩

  71. ​​ Prosecutor v Renzaho, Decision on Exclusion of Testimony and Admission of Exhibit, para. 13. ↩

  72. Leiden Guidelines, Guideline E4, citing Prosecutor v Bemba et al., Judgment pursuant to Article 74 of the Statute, ICC-01/05-01/13-1989-Red, 19 October 2016, para. 219. ↩

  73. Prosecutor v Tolimir, Judgment, paras. 63–66; Prosecutor v Krstić, Judgment, para. 108; Prosecutor v Blagojević and Jokić, Decision on Admission into Evidence of Intercept-Related Materials, para. 24. ↩

  74. Prosecutor v. Bemba, Public Redacted Version of “Decision on Admission of Materials”, para. 122. ↩

  75. Prosecutor v Bemba, Decision on the admission into evidence of deferred items, para. 9. ↩

  76. Prosecutor v Katanga and Chui, Decision on Bar Table Motion, paras. 13-14. ↩

  77. Fergal Gaynor, Dov Jacobs, Mark Klamberg, and Vladimir Tochilovsky, ‘Law of Evidence’, in Göran Sluiter, Håkan Friman, Suzannah Linton, Sergey Vasiliev, and Salvatore Zappalà (eds), International Criminal Procedure: Principles and Rules (OUP 2013), p. 1027. ↩

  78. Prosecutor v Bemba, Decision on the admission into evidence of deferred items, para. 9. ↩

  79. Prosecutor v. Ruto and Sang, Decision on the Joint Defence Application for Admission of Documentary Evidence Related to the Testimony of Witness 536, ICC-01/09-01/11, 15 July 2014, para. 11. ↩

  80. See Prosecutor v Ongwen, Trial Judgment, para. 555; Prosecutor v Tolimir, Judgment, para. 63. ↩

  81. For instance, in the Ongwen trial before the ICC, the Trial Chamber allowed prior recorded testimonies from a total of 49 witnesses to be introduced (Prosecutor v Ongwen, Trial Judgment, para. 254). See also, ICC RPE, Rule 68. ↩

  82. Prosecutor v Ongwen, Appeal Judgment, para. 562. ↩