The US Supreme Court, in a 5-to-4 vote, placed further limits May 4 on the ability of state convicts to appeal their cases in federal court. The court ruled a lower court was wrong when it ordered a Cuban immigrant convicted of a 1984 murder in Oregon to be granted a hearing in federal court to determine if his plea of "no contest" was unconstitutional because he had not understood his lawyer's explanation of the plea. Jose Tamayo-Reyes, who spoke little English, claimed he thought he was agreeing to be tried for manslaughter - not admitting he could not win the case. Justice Sandra Day O'Connor in dissent said the ruling "has changed the law of habeas corpus in a fundamental way." The court also further defined when federal judges can dismiss as "frivolous" certain lawsuits brought by convicts and others who cannot afford to pay normal court costs. The court, in a 7-to-2 ruling, said it is largely up to a federal judge to determine when an appeal is legally "frivolous" and thus need not be litigated. The ruling reversed a decision of the 9th US Circuit Court of Appeals, which had said a federal judge could dismiss a lawsuit against the government as "frivolous" only if the allegations "conflicted with judicially noticeable facts." And the court said a federal prosecutor seeking an indictment can deliberately withhold evidence from a grand jury that might show a suspect is innocent. On a 5-to-4 vote, the court ruled that because a grand jury is "separate from the courts," federal courts no longer have the au thority to throw out an indictment solely on the grounds that prosecutors withheld "substantial exculpatory evidence" from the grand jury. "Requiring the prosecutor to present exculpatory as well as inculpatory evidence would alter the grand jury's historical role, transforming it from an accusatory to an adjudicatory body," wrote Justice Antonin Scalia.