Introduction: Forensic psychiatry operates at the interface of two disparate disciplines: Law andrnpsychiatry. Forensic psychiatry is a subspecialty of psychiatry in which scientiï¬c and clinicalrnexpertise are applied to legal issues legal contexts Amanuel Mental Specialized Hospital is onernof the largest and oldest psychiatric hospital in Ethiopia; it is also the only hospital that givesrninpatient forensic psychiatry service at this time. To our knowledge, the clinical & criminalrnjustice characteristics of the 'insane' have never been a subject of study in Ethiopia. We are veryrnhopeful that this study will be beneficial for the improvement of the forensic service training ofrnmental health professionals and ultimately benefit those affected by the limitations ofrninformation and scarcity of research to pinpoint issues we can work on to better the carernprovided to forensic psychiatry patients. rn rnObjective: To describe cases and explain the reason for their acquittal due to being "criminallyrnirresponsible" in the forensic inpatient service at Amanuel Mental Specialized Hospital in a spanrnof 6.5 years (between 01/01/2015 and 08/01/ 2021 GC). rnMethods: A retrospective facility-based study was conducted in Amanuel mental specializedrnhospital for a study period of 6.5 years from January 2015-August 2021. Forensic reports werernused as a source of data, a data extraction sheet was used to collect data, and SPSS version 24rnwas used to analyze the data. Descriptive statistics are displayed in text, tables, and figures.rnVariables that showed association with the outcome variable using binary logistic regressionrnwere subjected to multivariate logistic regression. Statistical significance was declared at p-valuern< 0.05. rnResult: A total of 205 forensic reports of defendants were identified in the study period. Of this,rn15 (7.3 %) cases did not have a conclusive forensic opinion regarding criminal responsibility;rnthese cases were excluded from the analysis. The mean age of the defendants was 33.13 yearsrnwith a standard deviation of 10.6 years. This study also showed that the magnitude of insanerndefendants among patients who had forensic mental health assessment at Amanuel mental healthrnspecialized hospital was found to be 39.5 %. The study revealed from the cases who havernneuropsychiatric diagnoses 62.2 % were found to be "criminally irresponsible."rnrnConclusion & recommendation: The number of insane defendants among patients who hadrnforensic mental health assessment at Amanuel mental health specialized hospital was relativelyrnhigh. rnFactors that had an association with insane defendants include psychiatric diagnosis ofrnschizophrenia spectrum disorder, bipolar Ð† disorder, and disordered psychiatric condition duringrnthe time of assessment. Creating awareness about severe mental illness and early detection andrninitiation of treatment may contribute to the prevention of the offenses as a society and improvernthe quality of life for the clients.