A model for digital evidence admissibility assessment

Abstract

Riding on the tide of the current development in computing and internet technologies, criminals have transitioned to the use of computer systems and digital channels to commit crimes. This transformation of crime requires criminal justice actors to investigate, produce and present digital evidence through a process that is scientifically proven and legally admissible, but also capable of securing successful prosecutions. Even though previous efforts by criminal justice practitioners and researchers have contributed to the standardisation of digital forensics in a manner that has consolidated the scientificity1 of digital forensics as a forensic science, these approaches, processes and techniques have not addressed adequately the issue of admissibility of digital evidence in judicial proceedings. In other words, existing models and standards are generally investigative-focused, which has significantly ensured that digital forensics processes follow a specific scientific order. Despite these advances, the existing techno-legal dilemma pertaining to the admissibility of digital evidence in judicial proceedings remains unresolved. In order to address this techno-legal dilemma, the thesis presents a Harmonised Model for Digital Evidence Admissibility Assessment (HM-DEAA), a model that integrates both technical and legal determinants to establish digital evidence admissibility in judicial proceedings. In order to operationalise the HM-DEAA, this research introduces an algorithm to assess digital evidence admissibility and to determine the evidential weight of a piece of digital evidence, which is tendered in a court of law. This algorithm has been tested on both hypothetical and real cases as part of the HM-DEAA’s evaluation for its potential use in legal proceedings. In addition, an expert system has been introduced to automate the operationalization of the HM-DEAA. In practice, the HM-DEAA framework is expected to provide a harmonised techno-legal foundation for assessing digital evidence admissibility in the criminal justice sector. The model is expected to be used primarily by judges as a judicial tool in legal proceedings. The expert system is also expected to serve as an assessment tool for investigators, prosecutors and defence lawyers to evaluate digital evidence with regard to its potential use in court.