Dunham, however, claimed that these questions utilize a "non-clinical standard" which asks "a bunch of stereotypical questions a layperson would ask to determine intellectual disability."
Some of the questions are "derived from Lenny of 'Of Mice and Men,'" a fictional character in a John Steinbeck novel, he added.
Ultimately, he claimed, these questions "appear to be a gloss that Texas is placing over the clinical definition" of intellectual disability. Thus, the state is using a non-clinical standard to ultimately determine who will be executed, he said.
Both the American Psychological and Psychiatric Associations agree, stating in their brief supporting Moore's case that "there is a consensus among the mental health professions about how properly to diagnose persons with intellectual disability. Texas' approach to intellectual disability is inconsistent with this consensus."
In a recent death penalty case, Hall v. Florida, the state of Florida had set an IQ score of 70 as a benchmark in determining if someone was intellectually disabled. However, "the clinical community generally considers an IQ of 75 or below to be a qualifying score," Dunham noted.
Thus, he said, the Supreme Court ruled that Florida "deviated from the established national consensus," and "did so in a way that allows the execution of individuals who, under clinical practice, would be intellectually disabled," violating both its ruling in Atkins and the Eighth Amendment.
Texas has done a similar thing, he said. In adding this "non-clinical standard" of the Briseno factors as an additional burden of proof that someone is intellectually disabled, "Texas has deviated from the clinical consensus definition of what constitutes an adaptive deficit," he claimed.
He said the state "includes as eligible" for the death penalty "a range of people who would be deemed as intellectually disabled" under the commonly-accepted clinical method.
For instance, the state in 2012 used the Briseno factors and determined that Marvin Wilson, a man who scored a 61 on an IQ test, was eligible for the death penalty.
And, Dunham added, Texas only uses the Briseno Factors in death penalty cases. For other cases, like with applications for Social Services, Texas relies upon other clinical methods.
In October, Texas' bishops called for "the abolition of the death penalty."
(Story continues below)
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"Catholic teaching unequivocally states that 'if non-lethal means are sufficient to defend and protect people's safety from the aggressor, authority will limit itself to such means'," they stated, citing the Catechism of the Catholic Church paragraph 2267.
"This simply means if alternatives to the death penalty exist that serve to protect society from violent criminals, society 'must limit itself' to these other means. There can be no doubt such means exist today in the United States, including in the State of Texas," they continued.
Clifford Sloan, arguing on Moore's behalf before the Supreme Court on Tuesday, said the standard upheld by Texas' criminal court "relies on harmful and inappropriate lay stereotypes."
Justice Elena Kagan remarked to Sloan that "we could say that the Briseno standards are in conflict with the old Atkins standards, as well as the new ones."
"There wouldn't need to be a difference between the old ones and the new ones for you to win this case," she told Moore's lawyer, who agreed.
The justices then asked tough questions of Keller, wondering if the state was using the Briseno factors to make it harder for someone to prove their disability, and effectively cut down the number of people who are ineligible for the death penalty.