The United States was the first jurisdiction to adopt a rule that routinely excluded reliable evidence because it was obtained in an unlawful manner to deter illegal searches in the future. Reference is frequently made to the fact that the exclusionary rule is an anomaly, with the United Kingdom's absence of such a rule often being mentioned. The academic literature is filled with lamentations and defenses of this example of American exceptionalism, but takes no meaningful stab at explaining at the reasons for this uniqueness. I attempt to fill this gap in the literature. While the rule was adopted by the United States Supreme Court in 1886 or 1914, depending on how one reads the precedents, state courts, the real actors in criminal justice in the early twentieth century, did not begin to accept the rule until America began its Noble Experiment to stamp out to alcohol consumption in the 1920s. With Prohibition also came numerous searches for liquor, some justified many not, by a hoard of poorly trained and largely unfit officers recently hired to enforce the new law. The exclusionary rule came to be accepted as a means of curbing the excesses of these officers. I also suggest that there were real problems with choosing this as the method of regulating police -- a deterrent model premised on the exclusion of reliable evidence does little to address investigatory methods that risk wrongful convictions or unjustified uses of force. Prohibition's legacy is thus a rule of law that deters a pressing search and seizure concern from the 1920s, a rule that focused the supervision of judges on matters unrelated to the real concern of the twenty-first century, excessive force and wrongful conviction.
Prof. Oliver is associate dean for faculty scholarship, director of the criminal justice program, and professor of law at Duquesne University.