Earlier in 2024, I published an article on this site regarding the pending judgment of the International Criminal Court (ICC) in the case of Prosecutor v. Al Hassan. On June 26, 2024, the Chamber delivered its judgment. This article recaps the relevant case details and highlights the image-based evidence that was challenged by the defence during the trial. I also comment on the Chamber’s limited assessment of this evidence.
From an image-based evidence perspective, this case is significant because the prosecution relied upon advanced visual representations of key location evidence as part of its case and presented the testimony of the technical personnel who created the representations and supplemental image comparison evidence from a qualified expert to assist the Chamber with fact finding. The prosecution’s image-based evidence was challenged by defence counsel during cross examination.
The Defendant
The defendant Al Hassan Ag Abdoul Aziz was alleged to have been a member of Ansar Eddine (a movement associated with Al Qaeda in the Islamic Maghreb) and the de facto Chief of the Islamic Police. In this role, the defendant was alleged to have been involved in the work of the Islamic Court in Timbuktu, Mali.
The Allegations
The defendant was charged with and faced trial for the following crimes allegedly committed in Timbuktu, Mali, in the context of a widespread and systematic attack by armed groups Ansar Eddine and Al Qaeda in the Islamic Maghreb against the civilian population between April 2012 and January 2013:
a) Crimes against humanity – torture, rape, sexual slavery, and other inhumane acts including forced marriages and persecution.
b) War crimes – torture, cruel treatment, outrages upon personal dignity, passing of sentences without previous findings of a properly constituted court, directing attacks against buildings dedicated to religion and historic monuments, rape, and sexual slavery.
The trial opened in July 2020 and the evidence of all parties was completed in February 2023. Closing statements of counsel were presented in May 2023. The judgment of the ICC was scheduled to be delivered in January 2024, but this was ultimately delayed until June. He was convicted on some counts and acquitted on others, but these results are not germane to the discussion about the use of image-based evidence by the prosecution during the trial.
The Image-Based Evidence
The image-based evidence of interest in this case dealt with the allegations that the defendant took part in the destruction of mausoleums of Muslim saints in Timbuktu using Islamic police forces in the field. During their opening statement, the prosecution advised the Chamber that they would be relying upon an interactive platform created by SITU Research which was created based upon visual evidence gathered by the Office of the Prosecutor (OTP). This interactive 360º visual representation involved satellite imagery, drone images, ground-based panoramic images, and augmented reality allowing viewers to navigate within the visual environment. The SITU representation was tendered as demonstrative evidence only but was an important part of the prosecution’s visual case.
Because the SITU Research interactive platform was created based on visual evidence gathered by the OTP, several OTP witnesses prepared reports and some of those witnesses also testified at trial regarding their role in the creation of the underlying images. The purpose of their testimony was to establish the authenticity, integrity, and reliability of the underlying images. This in turn would lend validity to the SITU platform. Amongst the expert evidence presented by the prosecution was an expert in satellite imagery who utilized satellite images to show the location of relevant mausoleums and mosques in Timbuktu and to show images before and after their destruction. Some of those images were used in the SITU representation. An OTP technical witness testified regarding his role in the creation of panoramic images from drone and ground-based photographs resulting in a panoramic horizonal viewing area of 360º and a 40º vertical span. Cross examination of this witness focused on the potential for errors in the creation of the panoramas and the witness confirmed that errors could occur in a human driven process such as creating panoramas though no errors were specifically identified or acknowledged.
A second OTP technical witness testified regarding the creation of 360º panoramic images utilizing images taken by another member of the OTP, and his reliance upon metadata-recorded GPS coordinates for the individual images. The witness worked on several projects arising from three different missions by other members of the OTP to Timbuktu over a five-year period for the same case. For one mission, the witness used 3,864 JPEG images to create 201 panoramas for 15 different sites. Another mission generated 7,000 images. The witness was cross examined about the software used to create the 360º panoramas and described the limitations of the software, e.g. the number of images it can evaluate and include in a panoramic display.
The only expert who testified regarding the tendered imagery was an expert in geolocation and forensic image analysis who evaluated some of the images used in the SITU platform. The expert was asked by the OTP to perform image analysis and comparison to assist in identifying the locations shown in questioned multimedia files (satellite images, drone images, panoramas, and photographs). In cross examination, the expert was asked about the questioned and known images used for comparison and whether all the appropriate images had been examined.
The Judgment of the Chamber
The Chamber delivered its judgement on June 26, 2024 (ICC-01/12-01/18-2594-Red). ICC Chamber judgments are typically lengthy as the Chamber must address multiple counts and voluminous evidence. The judgment in this case, including two separate and partly dissenting opinions, is 872 pages long. Even lengthy judgments like this may not cover all the issues that were raised during the trial. Rather, the Chamber must assess the evidence and the arguments made by counsel and address the issues that are necessary to decide the case. Judges generally avoid commenting on extraneous issues.
Based on the cross examination by the defence of the witnesses noted above, it was reasonable to expect that the defence intended to challenge the validity of the SITU platform by casting doubt on the authenticity and reliability of some of the underlying images relied upon by SITU to create the tendered exhibit. It was foreseeable that a challenge might also be made to the image comparison evidence. No defence expert evidence was presented on these points. Despite the challenges raised during cross examination, these issues were not raised by defence counsel in written argument and presumably not in oral argument. As a result, the Chamber did not address them in their judgment.
It is very common in both international and domestic criminal prosecutions for defence counsel to raise issues in cross examination and yet not pursue them in argument. The purpose of cross examination is, in part, to test the waters and see if anything of value surfaces. I have observed defence counsel aggressively pursue issues in cross examination in trials that I have conducted only to have those issues fall away when it comes to arguing the case. That is a wise strategy since only issues that have merit should be argued. In this case, it is likely that defence counsel found that the evidence of the prosecution witnesses adequately established the authenticity and reliability of the advanced visual representations and their underlying images.
Since the advanced visual representations were essential in proving the destruction of the mausoleums and mosques, the Chamber made brief favourable references to the evidence presented. The Chamber specifically relied upon the expert evidence presented by the satellite imagery and geospatial data analyst expert regarding the analysis of the satellite image pre- and post-destruction. The Chamber also relied upon the video evidence showing the demolition of the monuments (para. 1031). The Chamber did not comment on the SITU platform or the panoramic images. If the Chamber had concerns about this evidence, a comment likely would have been made.
From an image-based evidence perspective, further judicial commentary in the judgment on the evidence presented would have been helpful but since it was not raised by the defence, there was no need for the Chamber to say more than the summary comments noted above. At most, this judgment could be cited as inferential approval of the advanced visual representations but that would not be a strong position for counsel to take.
The Use of Advanced Visual Representations
The interactive 360º visual representations used in Al Hassan and other ICC cases are not ground-breaking. They have been used by other international tribunals and in different national jurisdictions. However, they do mark a significant step forward from the traditional use of diagrams, and photographic and video imagery. These representations constitute a method of packaging data that requires technical skill to create and relies upon foundational visual, aural, and measurement data gathered in the field by investigators, experts, and other people in circumstances that are laborious and sometimes dangerous. The ability to view satellite images, before and after images of buildings subjected to destruction, drone imagery, and ground-based still and panoramic photographs and video all in one omnibus platform is very helpful to counsel and the court. These representations have not yet faced significant challenge in the ICC though should they be subjected to scrutiny their admissibility should be able to be established through the provision of robust expert evidence on authentication and representational accuracy.
Advanced visual representations such as those presented in Al Hassan show that these are very effective methods of presenting compendious and complex images in the courtroom. Provided the underlying images are authenticated and they are properly displayed in the courtroom, there is no compelling reason not to allow the use of such image-based evidence in court. I am confident that these advanced visual representations will be a common feature in ICC prosecutions. In time, they may garner further judicial commentary. However, if they are done correctly, that commentary will likely be sparing.