The International Criminal Court (ICC) in The Hague, Netherlands will soon deliver its judgement in the case of Prosecutor v. Al Hassan. 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. The purpose of this article is to provide important information about the case and the advanced visual representation evidence presented by the prosecution.
The Defendant
The defendant Al Hassan Ag Abdoul Aziz is 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 is 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 will be delivered in January 2024.
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.
Based on the cross examination by the defence of the witnesses noted above, it is 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. A challenge may also be made to the image comparison evidence. No defence expert evidence was presented on these points. It remains to be seen what comments, if any, the Chamber will make regarding the SITU platform evidence and the image-based evidence overall. Even though ICC judgments tend to be very thorough and lengthy, not all litigated issues will be commented upon by the Chamber if they are not material to the decisions to be made by the Chamber.
The Use of Advanced Visual Representations
The interactive 360º visual representations used in Al Hassan and other ICC cases were 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 there 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 will be interested to see if the Chamber addresses the use of these advanced visual representation in this case. The Chamber was expected to deliver its judgment in January 2024, but this has been delayed.