Rape Shield Evidence and the Hierarchy of Impeachment
Written By: Rosanna Cavallaro
The federal rape shield law creates a bar against the use of evidence of “other sexual behavior” of a complainant in a rape case, permitting such evidence only within strictly defined circumstances. Unlike most other evidentiary rules of exclusion, which define an impermissible use of otherwise relevant evidence but do not purport to enumerate an exhaustive list of permissible uses, Rule 412 reverses the ordinary approach of such rules and prohibits the use of any and all rape shield evidence unless it is explicitly permitted by the Rule. This rigid approach to rulemaking itself poses nearly impossible problems of foresight. As it must, this legislatively created rule recites that it yields in criminal cases where the exclusion of such evidence “would violate the defendant’s constitutional rights.” To date, the United States Supreme Court has recognized that those rights are implicated only where the exclusion of material pursuant to the rape shield rule represents a “denial of a defendant’s opportunity to impeach a witness for bias.” Although Article IV of the Federal Rules of Evidence deals with the substantive use of evidence, the Court approved this exception to the exclusion of rape shield material pursuant to a longstanding theory of impeachment, or general attack on the “credibility” or “reliability” of the central witness against the defendant. In so doing, the Court established a difference in treatment of rape shield evidence that defies both logic and common sense, pursuant to which one theory of impeachment may be pursued while all others are forbidden. While this would be merely disappointing in other contexts, where, as here, the difference purports to have a constitutional foundation, a closer look at the rationale and results seems warranted.
The Court has long recognized and reinforced a hierarchy of impeachment, allowing evidence on a theory of bias virtually without restriction, even while approving strict legislative regulation of evidence that impeaches on theories other than bias, such as impeachment through character for untruthfulness or impeachment by contradiction. Frankly acknowledging that these other theories are “less favored forms of impeachment,” the Court nevertheless gives little satisfaction to those seeking an explanation for this favoritism or wondering why one mode of impeachment exists on such a different footing from others that might, in individual cases, “bear on the accuracy and truth of a witness’ testimony[,]” and might in those instances be far more likely than bias evidence to be determinative of a jury’s assessment of a witness or a defense. Indeed, with respect to rape shield evidence, the rule that treats bias as the only constitutionally required theory on which prohibited material may be offered elevates impeachment through bias above even some substantive uses of that evidence. Yet the Court’s discussion of the basis for this exceptional treatment of bias evidence is deeply unsatisfying, and linked as it is to constitutional doctrine, begs for some coherent elaboration.
In this Article, I seek to place other theories, both substantive and impeaching, on an equal footing with that of bias, such that they, too, can be the basis, in appropriate cases, for admissibility of rape shield material. In doing so, I necessarily suggest that the long-established hierarchy of impeachment that governs in all criminal trials, for rape or any other crime, and that places bias above both character and contradiction as a basis for juror evaluation of witness reliability, is constitutionally insupportable and bears reconsideration.