What is the effect of the exclusionary rule on the application of the Fourth Amendment?

Analysis. United States v. Leon, 468 U.S. 897 (1984) has encouraged an empirical examination of the effects of the exclusionary rule and set the example itself in recognizing such research. Id. at 907, n. 6. A good place for a circuit court to start is the application of the rule by the circuit courts. Between 1980 and 1985 approximately 450 appeals were taken to federal circuit courts in which an issue was the suppression of the evidence of drug trafficking because of an alleged violation of the Fourth Amendment. The volume of appeals alone is suggestive of the uncertainties the rule generates. Intensive inspection of 250 of these 450 ¹ cases shows further that far from being a clear guide to police action and far from being a firm barrier to police excesses, the rule in its application depends on consideration of multiple small details. The rule is very fact-bound. The rule invites litigation focused on the facts. The litigation leads to review whose outcome is often affected by the forum and the particular panel hearing the appeal.

Federal constitutional protections should be uniform throughout the nation. Inspection of these cases shows startling variation by circuit:

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