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When Junk Science is a Life-or-Death Matter

Cassandra Stubbs,
Director Capital Punishment Project,
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May 20, 2011

Yesterday, three different groups asked the Supreme Court to step in and restore fairness and reliability to death penalty trials involving so-called “expert” testimony about future dangerousness. For Texas juries, the “future danger” issue determines whether a defendant lives or dies: before the jury can return a death verdict, it must find that the defendant would pose a future danger if not executed.

The groups filed friend-of-the-court briefs urging the Supreme Court to hear a case that centers on the discredited testimony of psychiatrist Dr. Richard Coons in the sentencing trial of Billie Wayne Coble. Prosecutors are seeking the death penalty for Coble, who had served almost 20 years on death row while his case was on appeal before he won a new sentencing trial. At the new sentencing trial, Dr. Coons told the jury that Coble was likely to pose a future danger even though Coble had an unblemished prison record: He had never received a single disciplinary write-up and was described by all as a positive contributor in prison.

This disconnect only make sense when the scientific bases for Dr. Coon’s testimony are examined. It turns out he didn’t have any. Dr. Coons could not cite a single article or book supporting his own subjective, idiosyncratic approach to deciding future dangerousness. He was unaware of the relevant body of literature discussing dangerousness risk assessments.

Unfortunately, Dr. Coons’s testimony in Coble’s case is far from unique. The brief filed yesterday by Texas mental health organizations points out that Dr. Coons has testified in scores of capital cases, and he is only one of a small army of state psychiatrists and psychologists who turn up in court regularly to present their own unscientific, unfair opinions dressed-up as expert testimony. Perhaps the most famous of the bunch, Dr. Grigson, a.k.a. “Dr. Death,” was expelled from the American Psychiatric Association.

For defendants facing the death penalty, the admission of this unreliable and unfair testimony is often deadly. As the brief filed by the American Psychological Association describes, juries are often more likely to credit this unfair and unscientific “expert” testimony precisely because it comes from doctors, whom juries are far more likely to trust.

In Coble’s case, the highest Texas court, the Court of Criminal Appeals (CCA), took an important first step by ruling that the admission of Dr. Coons’ testimony violated rules that require that expert testimony be reliable. The CCA inexplicably, however, concluded that the admission of unreliable expert testimony in a capital case does not raise any constitutional issues. Each of the friend-of-the-court briefs filed yesterday — like the petition we filed to have his case heard by the Supreme Court — asks the Supreme Court to step in to restore constitutional protection in Coble’s case, and in the future cases that will inevitably come if the CCA’s mistake is not corrected.

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