American Criminal Law Review
When the exclusionary rule prevents the prosecution from using evidence necessary to bring a case to trial, the rule deters illegality while raising no issue about how it might interfere with usual factfinding processes. However, when a case proceeds to trial although a court has suppressed some prosecution evidence, courts need to decide the extent to which the defendant may benefit from the absence of the proof without opening the door to its admission. The exclusion of any relevant evidence raises similar questions, and courts often say the exclusionary rule is a shield from suppressed evidence, but not a sword with which the defendant can inflict damage on the prosecution’s remaining case. Nonetheless, this Article argues courts err when they analyze whether the defendant “opened the door” to suppressed evidence with a metaphor appropriate for rules excluding evidence for different—and less weighty—reasons than encouraging respect for individual constitutional rights. Employing usual evidentiary tests for opening the door unduly diminishes the effectiveness of exclusion as a deterrent of police misconduct when investigators expect the potential evidentiary payoff will not be necessary to bring the case to trial, but will nonetheless be useful to obtain a conviction.
James L. Kainen,
Shields, Swords, and Fulfilling the Exclusionary Rule's Deterrent Function, 50 Am. Crim. L. Rev. 59
Available at: http://ir.lawnet.fordham.edu/faculty_scholarship/507