Propensity Evidence, Due Process, and the Limits of Arguments From History

My work this summer and last summer has focused my attention on California’s criminal law more than the criminal law of any other state.  Every once in a while, however, an errant citechecking click or an event in the news will clue me in to the criminal laws of other states.  One such citechecking click occurred during one of my earlier assignments, which led me to find an interesting difference between the law of California and the law of Iowa.

As a general rule, evidence about a defendant’s prior bad actions cannot be admitted to show that the defendant had a propensity to do bad actions.  There are, however, some exceptions to this rule.  Federal Rules of Evidence 413 and 414, for example, permit evidence of the defendant’s commission of prior sexual assaults and child molestation in cases where the defendant is charged with sexual assault or child molestation.  In a similar manner, California Evidence Code, section 1108 allows for the admission of prior commissions of sexual assault in cases where the defendant is charged with sexual assault.  These rules have been upheld despite defendants’ arguments that allowing propensity evidence violates due process.  The main California case on this point is People v. Falsetta, 986 P.2d 182 (1999).  The Falsetta court held that it was not clear that a ban on propensity evidence was a fundamental part of California’s legal history, noting that courts had historically been far more lenient in allowing evidence of propensity in sex offense cases.  The court further noted that even if the principle against propensity evidence were sufficiently fundamental in sex offense cases, 1108 did not unduly offend the principle because it was a narrow statute and subject to the limitations of other evidentiary rules.

In contrast, the Iowa Supreme Court struck down a similar rule, Iowa Code 701.11, in State v. Cox, 781 N.W.2d 757 (2010).  Recognizing that the general history of propensity in sex offense cases suggested that courts would sometimes allow evidence of prior sex offenses, the court clarified that Iowa courts would typically require the evidence of the prior offenses to be “relevant and material to some legitimate issue other than a general propensity to commit wrongful acts.”  Because propensity evidence had never been admitted solely to show the defendant’s propensity, and because there were longstanding “deep concerns” over admitting this evidence, the court held that 701.11 was unconstitutional.

After an initial reading, both of these cases seem to illustrate the importance of history in making an initial determination of whether a law violates due process, with the Falsetta court relying on ambiguity indicated by several cases and treatises and the Cox court relying on a rule drawn from a number of cases.  But both of these cases also illustrate the limitations of history in determining whether a law violates due process.  The Falsetta court noted that there were a number of limitations on 1108, with other rules still limiting evidence that is unduly prejudicial and the rule only applying to sexual assault prosecutions.  On the other hand, the Iowa statute contained the same limitations, but the Cox court still concluded that it violated due process.

The courts seemed to reach these different conclusions by focusing on different values throughout their due process analysis.  The Falsetta court focused on the importance of successfully prosecuting crimes that are typically committed in private, noting that propensity evidence will help victims bolster their credibility compared to the defendant.  The Cox court focused on the inherently prejudicial nature of propensity evidence and noted that past crimes are not probative of future crimes.  When two courts value fundamentally different concepts, it should not be surprising when they end up reaching different conclusions.