JOHNNY PAUL PENRY won't get to see Hollywood's latest death row film, "The Green Mile.'' That's because he is on death row himself, slated for execution in Texas on January 13. Like the lead character in the movie, Penry has the mind of a child -- and the government wants to execute him anyway.

There's a chance, however, that the issues raised in the film will help people like Penry some day.

Like the lead character in the movie, Penry has the mind of a child -- and the government wants to execute him anyway.

The United States is almost alone in the world in allowing this barbaric practice. At least 33 mentally retarded men have been executed since the United States reinstated the death penalty in 1976. Some experts estimate that as many as 10 to 15 percent of the 3,000 men and women on the nation's death rows are retarded.

A person is considered mentally retarded if he or she has significantly sub-average general intellectual functioning, which generally means recording an IQ score of lower than 70, and exhibiting deficits in adaptive behavior before the age of 18. An average IQ score is 100; Penry's measures at 54.

Many of the mentally retarded on death row have committed terrible murders. Being guilty of a capital crime, however, is not enough to warrant the death penalty; U.S. law reserves it only for the most culpable or blameworthy offenders, based on consideration of their background, character, motivation and circumstances of their crimes.

The mentally retarded can never meet the criteria of extraordinary blameworthiness. People with retardation are incapable of calculated, mature evil. A retarded person is simply not the same as other adults. They are childlike in many of their limitations: their ability to reason and develop skills needed to navigate in the world are permanently stunted.

They have grave difficulties with language, communication, learning, logic, foresight, strategic thinking, planning and understanding consequences. They have problems with attention, memory and comprehension.

They are limited in their ability to learn from experience, to control their impulses, to think in long-range terms or to understand causality. Children outgrow most of these limitations. Those who are retarded cannot.

Penry was physically abused as a child, has organic brain damage and is mentally retarded. Twenty-two years old in 1979 at the time he raped and murdered Pamela Mosely Carpenter in Livingston, Texas, he had then -- and has now-- the mental capacity of a 7-year-old.

In a 5-to-4 decision, the Supreme Court overturned his conviction because the jury had not been allowed to fully consider his mental impairments. But the court stopped short of ruling that the Eighth Amendment's prohibition on cruel and unusual punishment precluded execution of the mentally retarded. It concluded that there was insufficient evidence that the national ``standard of decency'' had evolved far enough to reject such executions.

It is a sad commentary that the standard of decency of almost every other country in the world exceeds that of the United States when it comes to the death penalty.

There has been progress, however: The federal government and 12 states specifically exempt people with retardation from capital punishment. Polls consistently show that even death penalty supporters believe people who are mentally impaired should not be executed. But in some two dozen states, including California, such executions are permitted.

Legislatures refuse to change state laws because of tough-on-crime sentiment, exacerbated by the grief and quest for vengeance of the murder victim's families, and the failure of officials and the public alike to understand the significance of mental retardation and the difference between guilt and culpability.

The execution of the mentally retarded also continues because their mental limitations make them even more vulnerable than other defendants to the often arbitrary and unfair treatment inherent in capital trials. In their characteristic quest to please authority figures, for example, mentally retarded defendants are likely to waive their rights without fully understanding them. Almost invariably poor, they are usually represented by court appointed lawyers who lack the skills, resources and commitment to handle any capital case, much less one involving a defendant with mental retardation.

Penry, who was resentenced to death by another jury, now faces execution in less than two weeks. Lawyers pressing last-minute appeals hope to convince the federal courts that national standards of decency have evolved since the original Penry decision and that the execution of any defendant who is retarded should be prohibited as unconstitutional.

No one argues that the mentally retarded should be free from criminal responsibility. But life imprisonment is sufficient to express society's outrage at horrible crimes, to hold offenders accountable and to protect society from further violence. It is time the United States join the world in recognizing the senseless cruelty of executing anyone with the mind of a child.

©2000 San Francisco Chronicle Page A19