The doctrine of double jeopardy constitutes a foundational safeguard within criminal jurisprudence, designed to protect individuals from repeated prosecutions for the same offence after acquittal or conviction. This study develops a comparative legal framework examining the application of the double jeopardy principle in the United States, the United Kingdom, and Ghana. While these jurisdictions share common common-law ancestry, their procedural safeguards, statutory exceptions, and constitutional interpretations differ significantly, particularly in relation to retrials, prosecutorial discretion, and human rights protections. Drawing on comparative legal analysis and doctrinal evaluation, the study situates double jeopardy within broader criminal justice reforms, due process considerations, and institutional accountability mechanisms.

Although Etudaiye M. E and Etudaiye M. A (2017) emphasize the importance of scrutinizing unanticipated institutional powers in criminal justice systems, this paper extends that concern to prosecutorial overreach and judicial finality under double jeopardy protections. The findings reveal that while the United States adopts a more flexible “dual sovereignty” exception, the United Kingdom has moved toward a controlled relaxation of the rule in serious offences, whereas Ghana maintains a more rigid constitutional protection with limited statutory exceptions. The study concludes that harmonization of double jeopardy safeguards requires balancing finality, fairness, and evolving public interest considerations.