Throughout South America, Southern and Eastern Europe, and East Asia, more than two dozen countries have transitioned to democracy since the 1980s. A remarkable number of these have adopted an exclusionary rule (mandating that evidence obtained unlawfully by the government is generally inadmissible in criminal trials) as part of broader legal reforms. Democratizing countries have adopted exclusionary rules even though they are not required to do so by any international treaty and there is no indication that there is widespread popular demand for such rules. This has occurred at a time when the rule has been weakened in the United States, the country that is often looked to as a model on this question.
What is it about transition to democracy that calls on these countries to introduce an exclusionary rule? It appears that experience with authoritarian rule has focused the new regimes on the danger of a powerful executive who exercises power arbitrarily. As the brief comparative overview in this Symposium Essay suggests, the exclusionary rule is adopted by fledgling democracies at least in part because it embodies the idea of restraining government power and promoting the rule of law.
This rule-of-law conception of the exclusionary rule is broader than the current understanding of the rule in the United States. Under recent U.S. Supreme Court jurisprudence, exclusion is justified only when it would deter police officers from violating constitutional rights and when the benefits of deterrence outweigh costs to the enforcement of criminal law. Under the rule-of-law conception, by contrast, the exclusionary rule is justified as a means of holding the executive within the limits of the law and preventing government lawlessness from becoming rampant. After comparing the two approaches to the exclusionary rule, the paper concludes with some tentative predictions about the future of the rule in the United States and in new democracies.
Jenia I. Turner, The Exclusionary Rule as a Symbol of the Rule of Law, 67 SMU L. Rev. 821 (2014)