Open source image-based evidence is a key source of potentially valuable evidence in international and national criminal investigations and prosecutions. However, there are significant challenges and limitations involved in the use of this free-range evidence. I spoke about the use of open source image-based evidence at a conference hosted by the Inner Temple in London this month as well as at the International Criminal Court in The Hague. The purpose of this article is to provide a brief overview of this challenging type of image-based evidence.
Open source image-based evidence (OS IBE) refers to the posting of images and video recordings to social media and other open source sites by anyone who chooses to do so. This evidence is both a benefit and a burden. It is a benefit because it can amount to a windfall of evidence from disparate sources in myriad locations and from varied perspectives, but it is also a burden because OS evidence may not be authentic or reliable and may adversely impact upon the search for the truth.
OS images may be real images acquired from trusted, untrusted, or unknown sources, as well as synthetic images created by image modification software, artificial intelligence and other image generators, and deepfakes. OS IBE poses many challenges including the fact that it is often created by parties with partisan biases who have an interest in portraying a certain perspective of captured events, whether accurate or not. It is often posted in anonymity and may be used to disseminate false information, which we have seen in the Russia-Ukraine conflict and the Israel-Gaza conflict. An interesting side effect that may arise from the use of OS IBE is that viewers may become wary and may no longer be inclined to believe images that are real.
OS IBE poses authentication limitations when there is no access to the original media as metadata is typically stripped from images during the uploading process. This makes assessing the integrity of images more challenging – not necessarily impossible, but certainly more challenging. Another limitation with OS IBE is volume. In May 2023, the Office of the Prosecutor at the International Criminal Court introduced OTP Link, a new platform that will accept OS evidence from submitters far and wide. So far, it has received 35,000 submissions per month with 125,000 file attachments in 140 languages. Though the OTP employs AI and machine learning to assess the submitted images, this preliminary assessment process does not generate admissible evidence. Trained analysts must still evaluate the selected images for evidential purposes. The volume is staggering, and the OS stream is likely to become a river of information that will need to be assessed.
OS IBE is not something to lament. Rather, it is potential evidence that has additional hurdles that must be cleared before it can become evidence. These hurdles involve authentication of the images, assessing their reliability, and interpretation of their content.
The onus is on the tendering party to authenticate IBE. At its most basic level, this means establishing that the evidence is that which the party claims it to be. Part of this process involves establishing image integrity. Active and passive forgery detection techniques can be used as part of this process depending upon whether access to the original image is available.
Images must be confronted by people who have the necessary knowledge and expertise to properly interrogate them and draw supported meaning from them. Images do not speak for themselves. Assessing image reliability involves looking for hallmarks of reliability. Can we access the original? Do we know the source of the images? Can we interview the photographer? Is there metadata to examine? Can a content-based analysis be undertaken? These tasks require expertise, forensic tools, and time.
Images must also be interpreted. Some images can be properly understood by viewers upon the provision of limited contextual information. Other images will require additional information for viewers to adequately comprehend their meaning. In other cases, expert interpretive assistance will be required as the images themselves are sufficiently complicated or semi-legible such that viewers are highly likely to misinterpret the images or fail to interpret them at all without assistance.
OS IBE is a potentially valuable tool in the search for the truth, but it must be robustly confronted to assess its authenticity, reliability, and interpretive value. These tasks must be undertaken by qualified personnel using the proper tools and the correct methodology.
Personal Note
In November 2023 I was awarded a PhD by Leiden University in the Netherlands. I have been working on my PhD since early 2020 and the subject of my research is on the use of non-textual evidence in international criminal prosecutions. At the same time, I was writing a book entitled Image-Based Evidence in International Criminal Prosecutions: Charting a Path Forward. I am pleased to announce that my book is being published by Oxford University Press and has a current release date of March 2024. The book is described by Oxford as “pioneering” and “an essential resource for anyone working with image-based evidence”. I will post further information shortly for those who want to pre-order the book.
Over the past six years, I have striven to provide relevant information about the use of image-based evidence in the courtroom, forensic video analysis legal issues, and legal issues involved expert witness testimony. I would be grateful if you would share information about his website with colleagues and others who you believe would value from the information that is provided herein.