Competing narratives: A comparative case study of prosecutors’ and defence lawyers’ interpretations of digital evidence

Source abstract

Digital evidence increasingly shapes charging decisions and judicial outcomes, yet its technical complexity raises concerns for equality of arms. This paper presents a comparative case study replicating a previous analysis of prosecutors with practising defence lawyers. Using identical materials and scenarios, it examines how role, access to information, and institutional assumptions shape evidentiary assessment. We compare prosecutors’ and defence lawyers’ judgements on the relevance, evidential weight, and verification needs of four types of digital evidence. Prosecutors in the original study accepted police-reported evidence at face value, integrating it into a coherent narrative of guilt. Defence lawyers likewise acknowledged its potential significance but adopted a verification-led stance, granting high weight only with access to raw data, provenance checks, synchronisation, and independent expertise. The findings raise concerns under Article 6 of the ECHR, highlighting systemic imbalances. We recommend reforms, including clearer reporting, early disclosure, institutionalised quality assurance of digital evidence, enhanced training, and expert support.