Opinion ID: 1940967
Heading Depth: 3
Heading Rank: 1

Heading: Appellant's Mental Capacity

Text: The government moved before trial to preclude appellant from presenting a diminished capacity defense. Appellant had previously given written notice that she intended to raise cognitive deficits, including mental retardation ... as a defense to the elements of the offense. The government argued that because diminished capacity is not a recognized defense in the District of Columbia, the proposed defense testimony was inadmissible, citing Bethea v. United States, 365 A.2d 64 (D.C.1976). In response, the defense argued that appellant's cognitive impairment [2] had a significant impact on commission of the elements of the [charged] offenses. Defense counsel claimed that mental retardation should be an exception to the basic principle that all individuals are presumed to have a similar capacity for mens rea,  citing Bethea, 365 A.2d at 88. Counsel argued that expert testimony would explain, as a form of accident or mistake defense, how [appellant] was unable to understand the consequences of her actions. The trial court granted the government's motion. The court noted that this court not only had rejected diminished capacity as a legal defense in Bethea, but had declined to change course in subsequent cases. See, e.g., Doepel v. United States, 434 A.2d 449 (D.C.1981). The court also observed that other courts with similar precedents considered evidence of mental retardation or a low I.Q. to be prohibited evidence of diminished capacity. Thus any evidence relating to [appellant's] mental retardation or cognitive impairment would be evidence supporting a defense of diminished capacity and is not admissible in the District of Columbia.