Evidence concerning eyewitness testimony given by people with mental retardation in court was reviewed. Despite general perceptions that people with mental retardation make incompetent witnesses, available evidence suggests that they can provide accurate accounts of witnessed events. The accounts are usually less complete than those provided by the general population and are greatly influenced by the methods of questioning. The sparse available evidence suggests that cross-examination methods may lead to memory distortion. The use of closed, complex, and leading questions and the absence of aids to recall may have a particularly adverse effect on people with mental retardation. Resulting errors could lead to a false conviction or acquittal. Future policy and research in this much neglected area were discussed.
This research was funded by a British Academy Post-doctoral Research Fellowship to the first author and an Economic and Social Research Council grant to both authors. We thank Steven Taylor and two anonymous reviewers for their helpful comments.