When assessing petitioner's mental capability, lack of detail on childhood tests is insufficient to establish that the childhood tests should not be relied upo, with the appropriate fixed margin of error.
Where the low end of the IQ scores is within the defined range, consideration of the second factor is the test is compulsory; a borderline test number can't be offset by other factors.
Court did not clearly err in considering childhood data, as petitioner has been incarcerated for most of his adult life. Adaptive strengths, particularly within the controlled environent of prison, are not necessarily relevant to the consideration of adaptive deficits.
Supreme Court precedeent prohibits capital punishment where the intellectual disability exists at time of execution.
DISSENT
Adaptive strengths developed in prison are relevant to the inquiry. Data insufficient to carry the petitioner's burden of proving disability; court shifted burden sub silentio. State statute also has a presumption against petitioner, requiring him to prove unconstitutionality.