“It is difficult to credit that a developmental intellectual disability can lie dormant and undiscovered for thirty-seven years and then spring full-grown, like Minerva from Zeus’s forehead, only when that person would be exempted from the death penalty if found so disabled. . . .
The best source of retrospective information concerning adaptive behavior during the developmental period is usually school records. Such records provide an objective, unbiased documentation of a person’s abilities at the most pertinent time–a time at which mental retardation or intellectual disability is most likely to be diagnosed if it exists. . . .
Some psychologists argue that factfinders should not consider prison behavior in assessing whether a death row inmate is intellectually disabled because prison is such a highly regimented society in which inmates are required to perform rote and simple activities. But courts should not become so entangled with the opinions of psychiatric experts as to lose sight of the basic factual nature of the Atkins inquiry: Is this person capable of functioning adequately in his everyday world with intellectual understanding and moral appreciation of his behavior wherever he is?”
Ex parte Cathey, No. WR-55,161-02, 2014 WL 5639162 (Tex. Crim. App. Nov. 5, 2014).