A psychologist who examined more than a dozen Texas death row inmates for intellectual disabilities has been banned by the state from performing similar evaluations in the future.
George Denkowski of Fort Worth, who has been a witness for prosecutors and defendants in death penalty cases, reached a settlement with the state Board of Examiners of Psychologists after other doctors and defense attorneys raised questions about his methods.
Denkowski admitted no wrongdoing, but agreed to stop performing intellectual disability reviews in criminal cases.
Defense attorneys say they hope to use Thursday's settlement to have appeals courts review the cases of at least 14 inmates now on death row and help those men avoid lethal injection. The order, however, says it can't be used as evidence to retry cases in which Denkowski has already testified.
Psychologists and defense lawyers have complained that he used unscientific methods and artificially inflated IQ scores in determining inmates' intellectual capabilities. In 2010, the American Association on Intellectual Developmental Disabilities manual urged "strong caution against practices such as those recommended by Denkowski."
Denkowski has published articles saying that social and cultural factors should be part of the intellectual exam. He argued that someone living in poverty or in a community where basics skills, such as using simple tools or maintaining personal hygiene, are not valued may lack those skills but not show true signs of mental retardation.
The U.S. Supreme Court in 2002 banned the death penalty for people with mental retardation.
"Once again, another junk science scandal has rocked Texas' death row," said Kathryn Kase of the Texas Defender Service, who represents former death row inmate Daniel Plata.
Denkowski testified in 2005 that Plata did not have mental retardation despite several tests that showed his IQ was under 70. Plata's death sentence was reduced to life in prison on appeal in 2008 because of his intellectual capabilities. He now lives with other disabled inmates.
Denkowski's attorney, Jennifer Andrews, did not immediately respond to message left at her office seeking comment.
Not all of Denkowski's testimony favored prosecutors. Denkowski testified for the prosecution in two cases where he found the inmates did have mental retardation.
In the case of James Clark, who was executed in 2007, a court overruled Denkowski's finding. And in the case of Michael Richard, who also was executed in 2007, Denkowski testified first that Richard wasn't mentally retarded but then changed his mind and said he was.
Denkowski was a defense witness for Elkie Lee Taylor and Michael Hall, who were both executed in 2008. Denkowski determined they were mentally retarded, but his findings were overruled by the courts.
Texas state Sen. Rodney Ellis, D-Houston, a member of the Criminal Justice Committee and chairman of the Innocence Project board, said the courts should review all cases with Denkowski's testimony.
"We cannot simply shrug our shoulders and sit by and watch while the state uses legal technicalities to execute these intellectually disabled men," Ellis said.