Eyes in the Sky: Clarifying Guidelines for Space-Based Imagery in Mass Atrocity Prosecutions

[Andre Kwok is a former United Nations legal consultant at the Supreme Court Chamber of the Extraordinary Chambers in the Courts of Cambodia. He was a Westpac Scholar at the National University of Singapore’s Faculty of Law and is currently a research assistant at the Australian Centre for Space Governance.]

Amid calls for criminal investigations into the atrocity crimes committed in Gaza and Ukraine, Nicholas Koumjian, the head of the Investigative Mechanism for Myanmar (IIMM), has recently announced the collection of “over 23 million information items,” which include satellite data. This evidence is piling up against the violence inflicted on Rohingya communities, leading to the world’s largest refugee crisis as half a million refugees have fled to Bangladesh.

After Myanmar completely banned outside investigators in 2021, high-resolution ‘before’ and ‘after’ satellite images have become crucial in monitoring the regime’s international crimes. While the IIMM is not a court, it has the mandate to gather evidence and prepare case files for national and international trials. Should trial proceedings occur, the high volume of satellite imagery will likely be under the spotlight regarding its evidentiary status.

This raises important questions about how to treat space-based evidence during its transfer from the IIMM to the courts in criminal proceedings. The uncertainty highlights the expanding role of digital forensics from space-based technologies, which have become essential in investigating mass atrocity crimes, thereby transforming our response in two major ways.

First, earth observation data, which includes open-source, time-stamped, and geospatial imagery, enhances the monitoring capabilities for international crimes. Since atrocity crimes often occur on a large scale, satellite imagery can reveal mass movements of people indicative of forced displacement or ethnic cleansing, the unlawful targeting of civilians in conflict areas, and the locations of mass graves suggestive of genocide.

Second, satellites can observe areas that are otherwise inaccessible due to ongoing armed conflict or government restrictions. In many conflicts, authorities often deny investigators ground access, which makes gathering evidence challenging. This challenge intensifies when witness testimony becomes hindered by accessibility and safety concerns during armed conflicts. Given the high burden of proof for international crimes, satellite imagery can bridge these gaps in traditional investigation methods and provide an aerial perspective to fact-finding processes.

Satellite imagery is not novel in international criminal trials. During the investigations stage, the United Nations Investigative Team to Promote Accountability for Crimes Committed by Da’esh/ISIL collaborated with UNESCO and the United Nations Satellite Centre (UNOSAT), relying on satellite technologies to map ISIL’s destruction of cultural heritage. In the trial stage, declassified CIA aerial images were used in UN-backed tribunals in Cambodia and the Former Yugoslavia and the International Criminal Court (ICC). Despite satellite imagery’s significant probative value—meaning their relevance or usefulness in proving an issue—challenges to their admissibility have been limited.

Currently, no clearly defined standards govern the admissibility, authentication, and interpretation of satellite imagery in prosecuting mass atrocity crimes. Rule 63(2) of the ICC’s Rules of Procedure and Evidence grants judges wide discretion in determining the types of admissible evidence, as well as the evidence’s weight and authenticity. This is the case despite the unique technological feature of satellite imagery, which may not be familiar to non-technical parties in the courtroom.

The absence of clear guidelines is concerning, given the rapidly increasing use of such imagery, especially considering its widespread use in presenting recent allegations of genocide against Russia and Israel. As the general population gains increased access to open-source platforms like Google Earth, and non-governmental organisations use open-access mapping technologies to lobby governments, concerns about evidentiary integrity arise. The simultaneous growth of digital disinformation and deepfake technologies, especially regarding the politically-sensitive nature of atrocity crimes, will likely become more prominent as citizens gain greater access to explore both legal and non-legal avenues of action. Given these developments, there is an urgent need for clearer guidelines to ensure satellite imagery’s consistency and integrity in judicial proceedings.

Unlike photographs, satellite images cannot be understood at face value. This limitation has led to a heavy reliance on expert witnesses to interpret satellite imagery in court, raising concerns about confirmation bias. Experts may unconsciously align their interpretations with the hypotheses of the employing party, potentially compromising the objectivity required in legal proceedings. Furthermore, this dependence may shift the focus from the raw data to the experts’ interpretations, risking the fairness of the trial by favoring the narrative of the party with more resources to hire prominent experts. Current approaches to expert evidence in international courts were established before the rise of such technologies; hence, the almost exclusive role of expert witnesses in interpreting satellite imagery to display the contextual elements of mass atrocity crimes must be further explored.

Authentication of satellite imagery is another crucial issue that requires further attention. Unlike traditional evidence, which can be corroborated through direct testimony or physical examination, satellite imagery necessitates a more complex verification process. Courts must rigorously evaluate the integrity of these images, considering factors such as the satellite’s calibration, the angle of capture, and how the image is presented in trial. This includes examining the technical specifications of the satellite, the conditions under which the image was taken, and any alterations made to the image before it is presented as evidence.

Hence, it is crucial to ensure an unbroken chain of custody from the moment a satellite captures the image to its presentation in the courtroom to prevent unauthorised alteration and tampering. To manage this, courts should upgrade document and secure storage systems management, along with transparent procedures for transferring and accessing the image. A breach in this chain of custody can cast doubt on the image’s reliability as evidence, potentially undermining its admissibility in court. Therefore, courts must address the unique challenges of authenticating satellite imagery to effectively utilise this technology in judicial proceedings.

Similarly, the rapid commercialisation of outer space raises unique challenges regarding data integrity when courts rely on commercial space assets in legal proceedings. The dual-use nature of private satellites, serving both government and commercial clients, complicates matters of impartiality. These entities may have commercial or political interests that influence the data they provide. Similarly, the variations in image resolution among private satellites from different countries and the diversity in space industry standards underline the necessity for stringent criteria to ensure that their imagery meets the requirements for court proceedings.

Given these challenges, the international legal community should clarify evidentiary standards concerning satellite imagery. This effort could include establishing admissibility standards for space-based evidence, setting minimum quality requirements, and developing authentication systems to verify satellite imagery. Simultaneously, reforms in evidence legislation in both international courts and domestic legal systems should reflect the growing debates and trends in prosecuting international crimes domestically under universal jurisdiction.

Courts could introduce new internal practices, such as standardising image calibration settings from various satellite providers and ensuring timestamp accuracy. Furthermore, efforts to clarify evidentiary requirements present an opportunity to tackle the unique challenges posed by commercially owned satellites, whose data are not initially tailored for legal proceedings. While the ICC introduced a cryptographic hashing system to track the chain of custody of evidence known as MD5, it has since become outdated and is considered highly insecure by current industry standards. Cybersecurity experts have gone so far as to declare, “No one should be using MD5 anymore,” citing the ease with which MD5 certificates can be forged. This fact is bizarre considering that the ICC is generally a well-regarded international institution, yet it continues to use a decade-old system introduced in 1992.

With the expected rise of satellite imagery in international criminal litigation, courts could respond to this fragility by introducing updated cryptographic and encryption technologies to strengthen e-signature and file authentication. These improvements would be integral to the tendering and file management processes, ensuring the integrity of satellite imagery and the broader spectrum of digital forensics.

Similarly, judges and counsel should prioritise training to effectively integrate space-based evidence into legal proceedings. This is critical, as the case of Prosecutor v. Jean-Pierre Bemba Gombo demonstrated that ICC judges determine the admissibility of evidence at the trial’s conclusion, with the Chamber ruling that they can do so if the tendered items appear, on their face, to be sufficiently authentic. Should parties wish to challenge satellite imagery, a clearer understanding of the strengths and weaknesses of the tendered space-based evidence is needed.

Efforts to strengthen digital literacy could consist of interdisciplinary collaborations between bar associations, forensic investigators, satellite imagery experts, and institutions such as the UNOSAT and the Office for Outer Space Affairs. The focus should be on presenting satellite data in the courtroom, managing evidence according to best practices, and inspecting an image’s technological features that may influence its presentation and interpretation during a trial.

With the developments of the IIMM and current negotiations around the Draft Convention on Crimes Against Humanity, the time is ripe to revisit our approach to space-based evidence in legal proceedings. The increased reliance on satellite imagery for investigating and prosecuting international crimes highlights the urgent need for reform. Courts should establish clear guidelines for the admission and use of space-based evidence, regardless of whether these conflicts result in criminal prosecutions.

If criminal proceedings arise, the integrity of the likely increased volume of space-based evidence will be contested. Due to this, the legal community must proactively address these legal and technical issues to ensure that satellite imagery can be used effectively and justly in accountability efforts for mass atrocity crimes.

The opinions expressed in this article are those of the author and do not reflect the views or positions of any institutions they represent.

This article was amended on 16 March 2024 to reflect that MD5 (and not M5D) is a cryptographic hashing system.