Man says he's too old, infirm to be executed

''While serving a life sentence for murder, Allen executed a plan to silence witnesses," Schwarzenegger said in a statement. ''Allen's crimes are the most dangerous sort because they attack the justice system itself. The passage of time does not excuse Allen from the jury's punishment."

Allen, who will turn 76 on the eve of his execution, would be the second-oldest person executed in the United States since the Supreme Court allowed capital punishment to resume in 1976. He often uses a wheelchair and had to be resuscitated after suffering a heart attack last year at San Quentin Prison.

''The spectacle of Mr. Allen being wheeled into the death chamber, unable to walk and unable to see those who have come to witness his execution, violates all standards of decency and would amount to nothing more than the purposeless and needless imposition of pain and suffering prohibited by the Eighth Amendment," said Annette Carnegie, one of Allen's lawyers.

The Supreme Court has said it is cruel and unusual to execute the mentally retarded, those who are so mentally incompetent they do not understand they are about to be executed or why, and inmates who killed when they were juveniles.

But the high court has never stopped an execution because of an inmate's advanced age or physical infirmities.

Sparing Allen could open the way for similar challenges from other sickly death row inmates.