The killing for which Elroy Chester was sentenced to death was as awful as they come, a clear violation of both law and morality.What the U.S. Supreme Court is being asked to review in his case is whether allowing the state of Texas to execute him would violate the U.S. Constitution's prohibition on cruel and unusual punishment.On Oct. 26, the justices could decide whether to hear arguments on the petition from Chester, who has been on Death Row since 1998. His lawyers argue that he has an IQ less than 70, can't function independently, has been considered mentally retarded by the Texas prison system and received that diagnosis upon his arrest for capital murder.On a larger scale, they argue that Texas assesses criminal defendants' mental retardation using factors that were "invented" by the Texas Court of Criminal Appeals, "are not rooted in the clinical standards, have no basis in the scientific literature, and do not reliably distinguish between those who are and are not mentally retarded."It's true that the state's highest criminal court outlined guidelines in a 2004 case called Ex Parte Briseno. There's dispute over whether they comply with the Supreme Court's 2002 Atkins v. Virginia decision that limited the use of capital punishment.The justices ruled that the Constitution bars the execution of mentally retarded convicted killers but let the states determine who fits the definition.The year before the Supreme Court's ruling, the Texas Legislature passed a bill prohibiting executions of mentally retarded defendants, but Gov. Rick Perry vetoed it.Chester had been condemned before the high court's decision, but he received a new hearing afterward.Using its 2004 criteria, the Court of Criminal Appeals ruled against him. In December, a panel of the 5th U.S. Circuit Court of Appeals did likewise, splitting 2-1.Judge Edith Jones, then the 5th Circuit's chief, emphasized that Chester had not proved he had adaptive deficiencies: "Petitioner carefully cased the house of his victims, located the telephone box, cut the telephone wires, entered through an unlocked door (presumably to avoid the noise that would accompany breaking in), disguised himself in a ski mask, and raped/sodomized the two women inside using all the precautions one might expect to see from a clever criminal." She said his actions were "hardly the work of a person with diminished mental capacity."Dissenting Judge James Dennis, however, said the issue is whether a state court can "make up its own unscientific and non-clinical definition of mental retardation."Chester's criminal record depicts a highly unsympathetic figure. He was released from prison in March 1997 after serving time for burglary. During the next 11 months, he committed about 25 burglaries in the Port Arthur area. In February 1998, he sexually assaulted two teenagers at gunpoint in their home then fatally shot their uncle, Willie Ryman III, a firefighter who had come to check on his nieces.Chester pleaded guilty to the murder, and a jury quickly sentenced him to death. According to court briefs, he also confessed to five other murders, five shootings and three sexual assaults, crimes that were confirmed through DNA and ballistics.There's no certainty that the Supreme Court wants to review the way Texas determines mental retardation for death penalty purposes. In August, the justices turned down a petition from Marvin Lee Wilson, whose lawyers argued that he was mentally retarded. He was executed Aug. 7.Apparently, the Court of Criminal Appeals developed its criteria on the grounds that clinical factors were too subjective. However, the court's guidelines might be just as problematic.Whether or not the Supreme Court accepts Chester's case, it's time for the Legislature to deal with yet another problematic area of Texas' death penalty.