The Supreme Court is considering an emergency appeal today filed on the behalf of a Georgia death row inmate who claims he should not be put to death because he is mentally retarded.

The man, Warren Lee Hill Jr., is set to be executed Monday.

The case highlights a controversy stemming from a 2002 Supreme Court decision , Atkins v. Virginia. Although the Supreme Court ruled that it was unconstitutional to execute mentally retarded individuals, it left it up to the individual states to determine how to assess mental retardation.

While many states use a standard called "preponderance of evidence," Georgia is the only state to require a much stricter standard, "beyond a reasonable doubt" in making this assessment.

Hill was convicted in 1991 of using a board to beat and kill Joseph L. Handspike. Both men were inmates at the Lee State Prison in Lee County Georgia. At trial several prisoners testified that Hill mocked the victim as he beat him. Hill was serving a life sentence for murdering his former girlfriend by shooting her with a handgun.

Lawyers for Hill argue that a lower-court judge found that Hill had an IQ of 70 and was mentally retarded under the standard of "preponderance of evidence."

In court papers they argue that their client faces imminent execution "despite the fact that a state court charged with determining whether Petitioner is mentally retarded, actually found Petitioner to be mentally retarded by a preponderance of the evidence."

"Georgia forces people attempting to invoke the death ineligibility under Atkins v. Virginia, to prove mental retardation, beyond a reasonable doubt, an impossible standard by any meaningful reckoning , especially for psychiatric diagnoses, " the lawyers say.

The Georgia Supreme Court upheld Hill's sentence.

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"In Atkins, the Supreme Court of the United States made clear that it was entrusting the states with the power to develop the procedures necessary to enforce the newly recognized federal constitutional ban on the execution of the mentally retarded, " the court said.

The Georgia Supreme Court said that the Georgia General Assembly "remains within constitutional bounds in establishing a procedure for considering alleged mental retardation that limits the exemption to those whose mental deficiencies are significant enough to be provable beyond a reasonable doubt."

Three judges writing in dissent note that Georgia was the first state in the nation to prohibit the execution of mentally retarded persons, but it is now the only state that requires condemned defendants to prove their retardation beyond a reasonable doubt.

"The state may still execute people who are in all probably mentally retarded. The State may execute people who are more than likely mentally retarded. The state may even execute people who are almost certainly mentally retarded. Only if a mentally retarded person succeeds in proving their retardation beyond a reasonable doubt will his or her execution be halted, " the dissent said.

Critics of Atkins think the Court should step in and clarify the ruling.

"The court has not shown much interest in wading back into the Atkins waters. I don't' know why it hasn't. It's been frustrating to watch as the promise of Atkins has been eroded in many states through the implementation of both definitions and procedures which make it virtually impossible to prove that anyone has mental retardation," says John Henry Blume, a professor of Law at Cornell.

"Currently a person could be determined to have mental retardation in some states but not others."

The problem says Robert D. Latzman, a clinical psychologist at Georgia State University, is that lawyers often look for black and white answers. "We don't do that in the psychology world. We don't play in yes and no's we play in statistics and probability. That makes 'beyond a reasonable doubt' an impossible standard to attain."

What is the difference between the standards? "It's a matter of confidence in the diagnosis. Under the legal definition of 'beyond a reasonable doubt' the burden of proof is higher."

The nephew of Handspike, Richard Handspike , has filed an affidavit saying that the victim's family members were never contacted by the District Attorneys Office prosecuting the capital case and that the family believes that a sentence of life without parole would be the "appropriate and just resolution" in the case. " The death penalty should not be imposed on Mr. Hill, in spite of what he did," the affidavit says.