Why Visual Literacy Matters

Visual literacy is a topic that I discuss in detail in my book and features in conference presentations and other teaching events in which I participate. The purpose of this article is to provide an overview of visual literacy and its relevance to images that are relied on by investigators, counsel, and the court in domestic and international criminal prosecutions.

Visual literacy refers to developing a suitable level of knowledge of image-based evidence (IBE) such that it can be used to its full advantage along with an awareness of its limitations. It is an important component in the evaluation and interpretation of images and is needed to form sound and informed judgements about their meaning. Merely viewing an image does not equate with understanding what the image has to offer, nor does it lead to visual literacy. Achieving suitable visual literacy requires abandoning the perception that images speak for themselves and that viewers can comprehensively digest and interpret their content without guidance. It causes viewers to exercise more critical discernment when assessing images and is ultimately needed to ensure that the court can correctly assess the legibility of images and render judgement upon them with a full understanding of what propositions they support or refute.

If people who use IBE as part of their fact-finding role, whether as investigators, technicians, experts, counsel, or the court, lack sufficient visual literacy and therefore do not fully understand the IBE under consideration, several problems may arise. First, images that are of value may not be selected for use at trial because the viewer does not fully understand what they have to offer. Second, images may be selected because they have been misinterpreted and are used for the wrong proposition. Third, images may be used at trial but not to their full potential. Finally, images may be misinterpreted by the court because counsel did not give the court sufficient evaluative, interpretive, and expert assistance. Thus, deficient visual literacy can give to the risk of erroneous judgement, the failure to find the truth, and miscarriages of justice. Given that judges generally lack robust knowledge about image alteration and creation, they may also wrongly perceive that the likelihood of such a thing occurring is unrealistically low.

Examples of counsel’s limited visual literacy have been found in domestic and international criminal prosecutions wherein the prosecution sought to rely on images found on Facebook. In these cases, the prosecution was under the misapprehension that such images were prima facie authentic and reliable. This stance incorrectly assumes that open source platforms like Facebook seemingly guarantee authenticity and reliability when these are things that must be proactively proven. Indeed, most open source sites should engender skepticism as the default preliminary assessment of their evidential value.

Visual literacy limitations exist at the judicial level as well though that will not always be apparent. In one recent domestic case, an appellate court overturned a conviction for murder in part because of a concern that the trial judge engaged in a forensic image comparison process without expert assistance and in a manner that would have been forensically unsound (R. v. Benn, 2026 ABCA 14). For example, despite acknowledging that the CCTV images were of insufficient quality to allow for definitive identification, the trial judge assigned weight to similarities between the questioned and known images. The Court of Appeal noted ‘…the risk that a trier of fact viewing poor quality video images of an unidentified perpetrator and comparing it to high-quality video image of the prime suspect would unconsciously expect to see significant similarities between the two.’ The Court also noted the risk of cognitive bias when untrained people seek to look for similarities between questioned and known images.

Cognitive bias, when applied in the evidential context, is defined as ‘the class of effects through which an individual’s pre-existing beliefs, expectations, motives, and situational context influence the collection, perception, and interpretation of evidence during the course of a criminal case’. Researchers note that there is a fallacy that advances in technology generally and AI specifically help to protect end users from cognitive bias. In fact, sometimes the biases can be embedded in the software itself, exemplified by facial recognition programs.

Along with cognitive bias, equality of arms remains an ongoing issue. While prosecutors are legally and ethically bound to seek out and disclose both incriminating and exculpatory evidence in the overarching search for truth, the defence still need to make their own proactive assessments of IBE. Defence counsel are often constrained in their ability to fully analyze IBE due to the lack of adequate and timely disclosure, access to underlying data, limited time and expert resources, and the daunting complexity of some IBE. These constraints impact the ability of defence counsel to properly assess tendered IBE from authentication, reliability, and interpretive perspectives. Interestingly, Norwegian researchers Berge and Sunde found in their recent study that prosecutors were more likely to accept digital evidence at face value and integrate it into the prosecution narrative, demonstrating institutional trust, whereas defence counsel were more focused on seeking verification through access to and examination of the digital data. This divergence in trust regarding the integrity and value of the evidence may be reflective of limited and unequal digital and visual literacy. These issues can be addressed in whole or in part with timely disclosure of IBE and underlying digital files including fully transparent forensic methodology employed by the prosecution, authentication-related information, and access to independent technical support and experts.

There will be cases wherein still images and videos have been modified in such a way that the opposing party and the court are highly unlikely to detect the deceptions without expert assistance. It is essential that investigators, counsel, and judges receive adequate training about the complexities of IBE, including its authenticity, integrity and reliability, and the need to seek expert assistance in some cases. Improving the visual literacy of key players is intended to heighten their awareness of potential issues associated with IBE. Lawyers and judges are not expected to solve the problem themselves, but they must be able to determine when there is a need to retain the services of a forensic imagery expert. Forewarned is forearmed.