Forensic Assessment of Psychological Fitness for Trial in Capital Offence Cases in Federal High Courts

The forensic assessment of defendants' psychological fitness to stand trial is a critical intersection of forensic science and the criminal justice system, ensuring that individuals with significant mental health impairments are not subjected to unjust proceedings. This study empirically examines forensic psychological fitness for trial assessments conducted in capital offence cases before Federal High Courts across six geopolitical zones between 2019 and 2024. A mixed-methods empirical design was employed, reviewing forty forensic psychological assessment reports, interviewing eighteen forensic psychologists and psychiatrists, and analysing court decisions on fitness determinations across Abuja, Lagos, Kano, and Enugu jurisdictions. The study evaluates the assessment instruments used, consistency of methodology across geopolitical zones, judicial responses to fitness findings, and systemic barriers to fair fitness determinations. Findings reveal substantial methodological inconsistency across jurisdictions, with some assessors using internationally validated instruments such as the MacArthur Competence Assessment Tool while others rely on unstructured clinical interview alone. Courts accepted unstructured assessment conclusions in seventy percent of reviewed cases, raising reliability concerns. Detention in inadequate custodial facilities during assessment periods was identified as a compounding factor in mental health deterioration. Recommendations include the adoption of a standardised forensic psychological fitness assessment protocol for Nigerian federal courts, capacity building for forensic psychiatrists and psychologists, and review of custodial conditions during assessment periods. Keywords: fitness for trial, forensic psychology, capital offence, Federal High Court, Nigeria.