By Professor Mary Berkheiser
In the death penalty case of Ybarra v. State, 247 P.3d 269 (Nev. 2011), Ybarra challenged the district court’s finding that he was not mentally retarded and therefore was not categorically excluded from imposition of the death penalty. This was a case of first impression concerning the proper analysis to be performed under the statutory definition of mental retardation in NRS 174.098, which contains three components: (1) significant limitations in intellectual functioning, (2) significant limitations in adaptive functioning, and (3) age of onset.
The Court began by spelling out the standard of review. The determination whether a capital defendant is mentally retarded is based on factual conclusions but requires distinctively legal analysis to determine whether the elements of mental retardation have been proven; therefore, an appellate court reviews such a determination as a mixed question of fact and law. Applying that analysis, the appellate court gives deference to the district court’s factual findings, so long as those findings are supported by substantial evidence and are not clearly erroneous, but the appellate court reviews the legal consequences of those factual findings de novo.
Examining the district court’s factual findings, the Nevada Supreme Court concluded that Ybarra failed to show the onset of his mental retardation before age 18, the established age for such a determination. Further, the court found that Ybarra’s evidence of limited intellectual and adaptive functioning was not credible; instead, it stood in contradiction to other credible evidence. Based on these findings, the Court ruled that the district court had properly rejected Ybarra’s claim of mental retardation.
