When lay jurors are unfamiliar with key factual issues presented in criminal trials, the risk of wrongful acquittal or conviction can be avoided by providing educative information about these issues to assist juries in understanding the evidence. This study illustrates a systematic research program devised to increase jury knowledge about child sexual abuse (CSA). The effectiveness of an educative intervention in the form of specialised knowledge presented via expert evidence that targeted common jury misconceptions about CSA was tested in the context of a simulated videotrial. A pretest-posttest research design was applied to measure mock-jurors' CSA knowledge gains attributable to the intervention and the extent to which accurate CSA knowledge predicted verdicts. In addition, individual juror decisions were compared with jury decisions following group deliberation. Results revealed that many jurors endorsed CSA misconceptions and that their knowledge predicted credibility assessments of the complainant and their verdicts. However, decisions by juries following group deliberations produced an unexpected increase in acquittals despite increased CSA knowledge after exposure to expert witness evidence. Applications of this research paradigm can assist courts and parties in determining the most effective method to use to enhance jury decisions in criminal cases involving specialised knowledge beyond the expertise of most lay jurors.