Challenges and Opportunities: Audio-Visual Evidence in International Criminal Proceedings

The following guest post was written by Jelia Sane and Chiara Gabriele. Jelia Sane is a barrister at Doughty Street Chambers, London, specialised in the areas of international criminal law, international humanitarian law and human rights. Chiara Gabriele is a Legal Advisor for the Great Lakes program at TRIAL International. She joined the NGO in 2015 and has been based in Bukavu (DRC) since 2017. 

(Imagine: Open University)

International criminal courts and tribunals (ICTs) have long admitted audiovisual material in evidence, including photographs, videos and audio recordings. Photographs and moving images have been relied on since the first war crimes trials at Nuremberg. In the 1990s, the International Criminal Tribunal for the former Yugoslavia (ICTY) and the International Criminal Tribunal for Rwanda (ICTR) considered satellite imagery and film footage captured by journalists, amongst others.

More recently, the establishment of the International Criminal Court (ICC), Special Court for Sierra Leone (SCSL), and Special Tribunal for Lebanon (STL) has coincided with the popularisation of the internet, in particular of social media, along with the proliferation of mobile phone and communications technology. Individuals are increasingly uploading potentially relevant and probative evidence of international crimes online, especially on social media platforms. Indeed, to date, over 4 million videos of the Syrian conflict have been uploaded on YouTube alone. There are more hours of footage of the Syrian conflict than have passed since the war began in 2011. ICC investigators and prosecutors are increasingly collecting user-generated digital and open-source evidence for use at trial. The Office of the Prosecutor collected digital evidence for the first time in 2008 in the  Bemba case and video evidence was introduced in Prosecutor v Thomas Lubanga Dyilo, the first trial before the Court. By 2011, this kind of evidence had been collected in the Kenya, Ivory Coast and Libya investigations. The Court now has an ‘e-Court Protocol’, designed to ensure  the “authenticity, accuracy, confidentiality and preservation” of the record of court proceedings.

Audio-visual evidence can be a valuable source of evidence in international criminal trials. Footage from mobile phones, photographs, and videos can link a suspect to the scene of a crime; pinpoint the time and place of an incident; capture dimensions of an event that may lie beyond the recollection of a witness; and provide a credible, real-time, and objective record of a situation. The risk that information will be lost, manipulated, or destroyed is reduced, particularly in cases where evidence is preserved in a digital format. At the same time, the widespread availability of audio-visual technologies and the proliferation of “citizen” journalists and “user generated” material can raise thorny evidentiary challenges for courts, in terms of establishing provenance, authenticity, and chain of custody, amongst others. These challenges have yet to be specifically addressed in the procedural rules of the ICTs, whose approach to date has largely been to assess evidence of this nature on a case by case basis and by reference to the standard rules and principles applicable to other forms of evidence.

Audio-visual material is generally admitted as a form of documentary evidence. The term “document” has been broadly interpreted in this context to mean  “anything in which information of any description is recorded”, this encompasses  paper documents as well as  photographs and the content of audio and video recordings If the material is stored on, received, or transmitted by, an electronic device such as a smartphone, it will also be considered as digital evidence. In both cases, the “document” itself may also be preserved as physical evidence. As with other types of evidence, there are no universal standards governing the admissibility of audio-visual material. However, the admissibility threshold in ICTs is generally low relative to that of national systems, particularly common law jurisdictions.

Trial judges at the ICC for example have wide discretion to admit any evidence provided that it is (i) prima facierelevant; (ii) prima facie probative; and (iii) sufficiently relevant and probative as to outweigh any prejudicial effect its admission may cause. Relevance turns on whether the evidence makes “the existence of a fact in issue more or less probable”. Probative value is considered in terms of the reliability and authenticity of the evidence, as well as the extent to which it is likely to influence the determination of a fact at issue. This is a fact-specific inquiry that takes into account numerous factors, including the origin, form, content and date of the documentary evidence; where and in what circumstances it was seized; the chain of custody after seizure; the corroboration of the contents of the document with other evidence; and the nature of the document itself (e.g. whether it contains any signatures or stamps). Trial judges must also consider the potentially prejudicial effect of admission. Open source or user-generated evidence may raise specific challenges in this regard. For example, if a video is exceedingly graphic, or attacks the character of the accused without shedding much light on the facts in issue, it may be excluded as prejudicial. As for evidentiary weight, this will turn on the intrinsic quality of the evidence and on the totality of the evidence admitted at trial.

Applying these principles to digital and open-source evidence can raise unique challenges. For instance, establishing the provenance and authenticity of a video may be difficult where the material has been submitted anonymously. Open source information will need careful authentication in order to ensure that it has not been fabricated or altered and that it refers to the events it purports to shed light on. These difficulties are compounded by the absence of specific procedural rules and the divergent approaches adopted by Chambers in their evaluation of evidence. Indeed, there is no consensus even in relation to when in the trial process, admissibility should be determined.

Investigators do have certain technological tools at their disposal. For example, authenticity can be established by reference to the metadata i.e. information about a digital file that is embedded within the file itself, such as the time and date when a file was created. Because metadata can be tampered with, verification that the material is what it purports to be is essential. This can be undertaken through the use of apps which allow for the encrypted transmission and storage of audio-visual evidence and the creation of a digital chain of custody.

Relevance, reliability, authenticity, probative value, evidentiary weight and prejudicial effect: this is the multifaceted examination that trial judges undertake when evaluating whether an item of evidence assists to establish context, crime and/or mode of liability, among others. The contribution of audio-visual evidence, and specifically user-generated digital evidence, to this exercise can be significant. Investigators and prosecutors are increasingly alive to this and open source investigations in particular have boomed in the last decade. This presents both tremendous opportunities and challenges and will continue to do so, as technology develops.

It is against this background that, in December 2019, TRIAL International published “La preuve audiovisuelle devant les instances internationales: techniques et admissibilité”,  a handbook for practitioners on the uses of audio-visual evidence in international criminal proceedings. The handbook provides a comprehensive analysis of the case law of the ICC, the ICTY, ICTR, SCSL, and the STL regarding the admissibility and weight of audio-visual evidence, including open-source and digitally generated evidence. In the absence of uniform legal guidelines on the collection, preservation, admissibility and weight of audio-visual, and particularly open source and digital evidence, TRIAL International has sought to bring together, in one practical guide selected cases of the ICTs on this topic in order to fill a gap in the existing literature and assist practitioners grappling with these issues.

As Chiara Gabriele, Editor of the handbook, stresses: “As the recent conviction for the Kamananga and Lumenje massacres (DRC) illustrates, the use of technology presents a wealth of opportunities to advance accountability for mass crimes, both at the domestic and international levels. Our challenge now is to ensure the footage is correctly collected and preserved, in a way that will ensure optimisation at trial.”


About Mark Kersten

Mark Kersten is a consultant at the Wayamo Foundation, a Senior Researcher at the Munk School of Global Affairs, and a law student at McGill University Law School. He is also author of the book, 'Justice in Conflict - The Effects of the International Criminal Court's Interventions on Ending Wars and Building Peace' (Oxford University Press, 2016).
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1 Response to Challenges and Opportunities: Audio-Visual Evidence in International Criminal Proceedings

  1. El roam says:

    Great post. It would be just worth to note, new approaches and techniques in this regard( although, in terms of admissibility, we are quite far yet):

    ” Forensic Architecture”

    I quote from Wikipedia:

    ” Forensic Architecture is a multidisciplinary research group based at the University of London that uses architectural techniques and technologies to investigate cases of state violence and violations of human rights around the world. The group is led by architect Eyal Weizman.[1]

    The agency develops new evidentiary techniques and undertakes advanced architectural and media research[2] with and on behalf of communities affected by state violence, and routinely works in partnership with international prosecutors, human rights organisations and political and environmental justice groups.[3]

    The agency is an interdisciplinary team of investigators including architects, scholars, artists, filmmakers, software developers, investigative journalists, archaeologists, lawyers, and scientists. It undertakes investigations in human rights violations by states or corporations, on behalf of civil society groups.[4]

    The group uses advanced architectural and media techniques to investigate armed conflicts and environmental destruction, as well as to cross-reference a variety of evidence sources, such as new media, remote sensing, material analysis, and witness testimony.[5][6]

    Forensic architecture is also an academic field and an emergent field of practice developed at the Centre for Research Architecture, at Goldsmiths, University of London. It refers to the production and presentation of architectural evidence, relating to buildings and urban environments and their media representations.[7] ”

    For the rest, we won’t stay young here no more.



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