The US Supreme Court has given new hope to anti-death penalty campaigners by overturning the sentence on a mentally handicapped Texas man who has been on death row for 20 years.
Meanwhile, government prosecutors have asked a federal judge to deny any further delays in the execution of Timothy McVeigh, the Oklahoma bomber, scheduled for next Monday.
Ruling that the judge in John Paul Penry's case had given the jury inadequate instructions about how to regard his mental condition, the Supreme Court quashed the verdict for the second time on Monday, by six votes to three.
Penry, who has an IQ of between 51 and 63, is said to have the mental capabilities of a normal seven-year-old. In 1989 the Supreme Court ruled against his original death sentence on similar grounds, and Penry was put through the sentencing process again, with the same result.
Whether he will face it a third time depends on whether the state Governor, Mr Rick Perry, signs a bill banning the execution of the mentally handicapped.
The Supreme Court decision may allow a number of other Texas death row cases to be reopened, but is also an important testing of the waters in the Supreme Court for a legally more critical appeal pending on the substance of the issue, whether the execution of the mentally handicapped violates the Constitution. It is expected to rule on McCarver v North Carolina next year.
The last time the court dealt with the issue, in 1989, it ruled not to overturn such sentences until it was clear that to do so would reflect a national consensus against the execution of the mentally handicapped. Then only two of the 38 death penalty states prohibited it; now 14 do.
Opposing Monday's decision were the Supreme Court's three most conservative members, Chief Justice William Rehnquist, Justice Antonin Scalia and Justice Clarence Thomas. Justice Thomas's dissenting opinion found the instructions to the jury unambiguous and the state court decision "objectively reasonable".
The majority opinion, in the name of Justice Sandra Day O'Connor, said that the jury instructions in Penry's trial for rape and murder did not allow jurors "to make a reasoned moral response" to the mitigating evidence offered by his lawyers of retardation and a history of severe abuse as a child.