October 14, 2009

Texas death case illustrates Atkins quagmire

The U.S. Supreme Court's 2002 decision in Atkins v. Virginia to outlaw the death penalty for mentally retarded defendants has opened up a "welter of uncertainty" in courts around the nation. So-called "Atkins inquiries" into whether a defendant is mentally retarded rely heavily on mental health experts, who may disagree on everything from the definition and identification of mental retardation to whether the specific defendant meets the threshold criteria.

This familiar spectacle of dueling experts takes a particularly ominous turn when experts misstate the science in these high-stakes (literally, life or death) cases. Fact-finders are often ill-equipped to disentangle the highly complex technical and scientific issues pertaining to whether or not a defendant meets the magic cutoff that will spare his life.

Over at his new blog, Intellectual competence and the death penalty, Kevin McGrew critically analyzes the latest case exemplifying these legal pitfalls, especially in the increasingly common situation in which the defendant is from another culture or speaks a language other than English. The case is that of Virgilio Maldonado, out of the U.S. District Court for the Southern District of Texas.

McGrew believes this case represents "a miscarriage of justice" that typifies the problems inherent in Atkins inquiries:
"The courts appear ill-equipped to handle the complex psychological measurement issues presented, issues that are, at times, confounded by the inclusion of data from dubious procedures, interpretations of test scores that are not grounded in any solid empirical research, and the deference to a single intelligence battery (the WAIS series) as the 'gold standard' when a more appropriate instrument (or combination of WAIS-III/IV and other measures) might have been administered, but the results of the more appropriate measure are summarily dismissed based on personal opinion (and not sound theory or empirical research)."
Those of you who practice in this area will be interested in McGrew's in-depth dissection of the IQ testing problems when defendants are not proficient in English language. Often, tests are wrongly selected, misadministered and misinterpreted under these circumstances.

In the Maldonado case, the prosecution's psychological expert decided to upwardly adjust the defendant's IQ score to a specific number based on his "clinical judgment" as to cultural and educational factors.

"It’s around the 80s, I guess, if you had to pin me down. Around the 80s; somewhere in there," the psychologist testified.

As McGrew points out:
"Adjusting obtained IQ scores, either up or down, … in the absence of any scientifically established procedure … is troubling and is not consistent with accepted psychological assessment practices or standards."
McGrew also critiques courts' frequent practice of putting the WAIS tests on a pedestal as the "gold standard," to the point of dismissing Spanish-language tests that are normed on relevant Spanish-speaking populations.

McGrew's in-depth analysis is HERE. The 144-page Maldonado decision is online HERE.

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