I. INTRODUCTION In Atkins v. Virginia, (1) the Supreme Court ruled that it was unconstitutional to execute persons with mental retardation. (2) The Atkins Court concluded that statutory definitions of mental retardation (MR) should generally conform to the then current definitions offered by the American Association of Mental Retardation (AAMR) and the American Psychiatric Association (APA). (3) These clinical definitions include three basic criteria for diagnosing MR: (1) significant subaverage intelligence with (2) substantial impairment in adaptive functioning that (3) has been evident since the developmental period. (4) Although general agreement about these three components may lead to the impression that diagnosing MR is a straightforward process, there is considerable debate about the appropriate measures, procedures, and information that should be used to diagnose MR, especially in capital cases. This article presents the results of an empirical study which used trial transcripts to identify the types of information about MR that are presented to jurors in capital cases, with an emphasis on information about adaptive functioning.
