The Presumption of Innocence as a Source for Universal Rules on Digital Evidence:The guiding principle for digital forensics in producing digital evidence for criminal investigations

This paper proposes a conceptual framework for the development of digital evidence rules in technology-assisted investigations based on the presumption of innocence. The presumption of innocence (PI) is examined as a general principle of criminal procedure to delineate its scope and application on pre-trial and clarify its role for the development and harmonization of practical and enforceable rules for digital evidence. It is demonstrated that PI provides a theoretical background for digital evidence regulation, digital forensics standards, and harmonized rules on the use of technology for investigative purposes irrespective of jurisdictional differences. The derived PI-based evidence rules reveal missing techno-legal policy for their implementation in digital evidence systems and processes. After introducing the wide-spread use of digital evidence by law enforcement in the course of criminal investigations and proceedings (I.), this article reviews the schools of thought regarding the impact of PI on evidence procedures focussing on the question whether PI’s protection against wrongful conviction could support measures against arbitrary and intrusive investigations (II.). The reviewing analysis strives to balance contradictory opinions about the scope and application of the PI, before examining digital forensics specifics in the context of the derived PI-based evidence rules to identify techno-legal policy tailored for the digital investigations and its effective implementation in digital evidence systems (III.)