For defendants with retardation, procedures vary: expert witnesses in death penalty cases must know standards of proof differ from state to state.

SAN FRANCISCO -- The U.S. Supreme Court decision that executing mentally retarded offenders is unconstitutional provided little guidance on how to implement the ruling. The result has been a mishmash of procedures that vary widely from state to state, Dr. Clarence Watson and Dr. Kenneth Weiss said at the annual meeting of the American College of Forensic Psychiatry.

"It's important to know what the procedures are where you live and where you practice," said Dr. Weiss, a forensic psychiatrist in Bala Cynwyd, Pa. Psychiatrists and other mental health professionals are likely to become involved as expert witnesses in these cases.

Seventeen of the 36 death penalty states had statutes regarding mental retardation and the death penalty before the Supreme Court's 2002 decision in Atkins v. Virginia. An additional eight states have enacted statutes since the Atkins decision. Eleven legislatures have so far been silent on the matter, but among those are five in which there is a relevant case law. In the absence of a statute or case law, judges, prosecutors, and defense attorneys must rely on adhoc procedures. (See graphic.)

"Because there's a constitutional ban on executing the retarded, courts and states, and judges have to make it reasonably easy--without tipping it too much in the defendant's favor--for individuals with mental retardation to prove it," said Dr. Watson of Jefferson Medical College, Philadelphia. "They can't put too many roadblocks in the way."

The laws and procedures vary based on these considerations:

* Standard of proof. Must mental retardation be proved "beyond a reasonable doubt" as guilt or innocence is? Can it be proved by a mere "preponderance of the evidence," meaning anything more than 50% certainty the standard in civil cases? Or should the standard be "clear and convincing evidence," often described as 75% certainty?

* Burden of proof. Is this burden on the prosecution or the defense?

* Fact finder. Who makes the final determination, the judge or the jury?

* Timing. Is the determination made before the trial, during the penalty phase, or both?

* Definition of mental retardation. Should the definition be based on the DSM-IV-TR or the slightly different definition used by the American Association of Intellectual and Developmental Disabilities (formerly the American Association on Mental Retardation)?

A consensus appears to be developing in favor of the DSM-IV-TR definition, Dr. Weiss said. This definition relies on IQ scores of about 70 or below, at least two standard deviations below the mean; impairments in adaptive functioning or the effectiveness by which individuals cope with common life demands; and an onset before age 18 years.

In terms of IQ, most states use a threshold of 70 or below, but in California, Indiana, Georgia, Missouri, Utah, and Nevada, no mention is made of IQ-specific scores. In Arizona and Arkansas, the threshold is below 65; in Illinois, it is below 75.

In terms of age of onset, most states are satisfied with 18 years, but the age of onset is 22 years in Indiana, Maryland, and Utah. Georgia mentions only the individual's developmental period, and New Mexico and Nebraska make no mention of either age or developmental period.

And if that's not confusing enough, "there's no standard [on how to] determine deficiencies in adaptive functioning," Dr. Weiss said.

Most states have settled on "a preponderance of evidence" as the standard of proof, but in Georgia, it's "beyond a reasonable doubt."

In Arizona, Delaware, Indiana, Colorado, and Florida, that standard is "clear and convincing evidence." And North Carolina has a hybrid standard, with the judge using clear and convincing evidence at pretrial and the jury using a preponderance of the evidence during the penalty phase.

Although an appellate court in New Jersey required the prosecution to prove a negative: that the individual was not mentally retarded beyond a reasonable doubt, the New Jersey Supreme Court put the burden on the defense to prove mental retardation by a preponderance of the evidence.

More recently, New Jersey abolished the death penalty.

Dangers are inherent in having all of these variations in definitions and procedures, Dr. Weiss and Dr. Watson said at the meeting.

Expert psychiatric witnesses have to be expert not only in diagnosing mental retardation, but in the specific procedures in their jurisdictions as well. Furthermore, the different standards of proof protect some and not others, indicating an uneven application of the Eighth Amendment, which prohibits cruel and unusual punishments.

In this respect, the difficulty of arriving at fair procedures for taking into account a defendant's mental retardation is another example of the difficulty of creating fair procedures for administering the death penalty with any defendant, regardless of the person's intellectual functioning.

BY ROBERT FINN

San Francisco Bureau