A Constitutional Right to Exclude Evidence

The Supreme Court has held that criminal defendants have a constitutional right to introduce evidence and a constitutional right to receive evidence, but it has never recognized a constitutional right to exclude evidence. Specifically, the Supreme Court has issued numerous rulings finding that the Due Process Clause demands that (1) defendants have the right to present a defense that trumps the rules of evidence; (2) the prosecution must disclose material exculpatory evidence to the defense; (3) the State has certain duties to preserve evidence so that it can be disclosed to the defense; and (4) any discovery obligations on defendants must be accompanied by reciprocal obligations on the prosecution. As a result, defendants know how to assert these rights, and courts have clear guidance to decide whether they were violated, allowing for wrongful convictions to be both prevented and overturned. Conversely, the Court has never made clear the circumstances in which the State’s admission of unfairly prejudicial evidence violates a defendant’s right to due process. In the absence of such a ruling, courts frequently admit evidence that poses a high danger of unfair prejudice unless it merely has minimal probative value. As a result, wrongful convictions connected to such evidence can neither be corrected nor prevented. This Article argues that courts should recognize a constitutional right to exclude evidence. Under this right, even if unfairly prejudicial evidence satisfies the rules of evidence, its admission would violate the Due Process Clause if it renders a defendant’s trial fundamentally unfair.