The effect of expert witness testimony about rape trauma reactions on juror decision making

Crime statistics on rape indicate that very few rapes are reported to police, and far fewer of those reported result in arrest, prosecution and conviction. Jurors in rape trials have been shown to believe inaccurate information about rape victims. In order to improve juror knowledge, psychological expert witness testimony on the reactions of rape victims (RTR testimony) has been used in many rape trials. Although most courts have upheld the admission of RTR testimony for the purpose of informing the jury about general reactions to rape, there is a great deal of disagreement over whether or not an expert witness should be allowed to diagnose a complainant with Post Traumatic Stress Disorder in relation to the rape. Testimony about alleged victims' diagnoses has been excluded from rape trials due to concern that such testimony might invade the juror's province (i.e., offer a legal decision to the jury under the guise of a diagnosis). The impact of different levels of RTR testimony on juror decision making was examined in this study. Empathy for the rape victim (Rape Empathy Scale), rape myth acceptance (Rape Myth Acceptance Scale), and juror verdicts were compared among participants who read an acquaintance rape trial and were exposed to one of two levels of RTR testimony or a no-expert control group. Analysis of variance and chi square analyses were used to examine the differences among the three expert witness groups with regard to empathy for the rape victim, rape myth acceptance, and verdict. Results demonstrated that exposure to the expert witness testimony groups did not differ in their level of empathy for the victim or their level of rape myth acceptance in comparison to the no-expert control group. A statistically significant relationship between exposure to RTR testimony and verdict was found with slightly more not guilty verdicts given by the no-expert control group in comparison to the expert witness testimony groups. These findings suggest that RTR testimony may have less of an impact on juror decision making than previously believed.