Developing a Theoretical Framework for Forensic Evidence Integration in Nigeria’s Criminal Justice System

The integration of forensic science evidence into criminal justice processes is determined by an interplay of institutional, epistemic, and legal factors that existing theoretical frameworks inadequately explain for the Nigerian context. This doctoral study develops an original theoretical framework for forensic evidence integration in Nigeria's criminal justice system, drawing on critical analysis of institutional theory, epistemological sociology of science, and legal evidence philosophy. A qualitative constructivist grounded theory design was employed, conducting sixty in-depth interviews with forensic scientists, prosecutors, defence lawyers, judges, and senior police officers across all six geopolitical zones, supplemented by institutional document analysis of forty-two court decisions involving forensic evidence between 2018 and 2024. The study maps the multi-level factors governing forensic evidence transition from laboratory to courtroom, identifying institutional capacity, inter-professional epistemic trust, judicial scientific literacy, and prosecutorial decision-making as the four primary integration dimensions. An original Forensic Evidence Integration Model (FEIM) is constructed, theorising the dynamic interactions between these dimensions and their relative influence on evidence admissibility and case outcomes across Nigeria's diverse jurisdictional contexts. The FEIM provides a theoretically grounded diagnostic tool for identifying systemic integration failures and a framework for designing evidence-based reforms. The study makes an original theoretical contribution to forensic science policy and legal scholarship, with practical implications for judicial training, forensic service governance, and inter-professional coordination. Keywords: forensic evidence integration, theoretical framework, criminal justice, Nigeria, grounded theory.