U.S. executions are all but sure to resume soon after a nationwide halt, cleared Wednesday by a splintered Supreme Court that approved the most widely used method of lethal injection.

Virginia immediately lifted its moratorium; Oklahoma and Mississippi said they would seek execution dates for convicted murderers, and other states were ready to follow after nearly seven months without an execution in the United States.

Voting 7-2, the conservative court led by Chief Justice John Roberts rebuffed the latest assault on capital punishment, this time by foes focusing on methods rather than on the legality of the death penalty itself. Justice John Paul Stevens voted with the majority on the question of lethal injections but said for the first time that he now believes the death penalty is unconstitutional.

The court turned back a challenge to the procedures in place in Kentucky that employ three drugs to sedate, paralyze and kill inmates. Similar methods are used by roughly three dozen states.

Death penalty opponents said challenges to lethal injections would continue in states where problems with administering the drugs are well documented.

The case decided Wednesday was not about the constitutionality of the death penalty generally or even lethal injection. Instead, two Kentucky death row inmates contended that their executions could be carried out more humanely, with less risk of pain.

The inmates "have not carried their burden of showing that the risk of pain from maladministration of a concededly humane lethal injection protocol, and the failure to adopt untried and untested alternatives, constitute cruel and unusual punishment," Chief Justice John Roberts said in an opinion that garnered only three votes. Four other justices, however, agreed with the outcome.

Roberts also suggested that the court will not halt scheduled executions in the future unless "the condemned prisoner establishes that the state's lethal injection protocol creates a demonstrated risk of severe pain."

States can avoid this risk by using the three-drug procedure approved in the Kentucky case, Roberts said.

Justices Ruth Bader Ginsburg and David Souter dissented.

Executions have been on hold since September, when the court agreed to hear the Kentucky case. The justices stepped in to halt six executions, and many others were put off because of the high court's review.

Forty-two people were executed last year out of more than 3,300 people on death rows across the country.

Wednesday's decision was announced with Pope Benedict XVI, a prominent death penalty critic, in Washington and the court's five Catholic justices _ Roberts, Samuel Alito, Anthony Kennedy, Antonin Scalia and Clarence Thomas _ headed to the White House for a dinner in his honor. All five supported the lethal injection procedures.

The court separately heard arguments Wednesday on the constitutionality of the death penalty for people convicted of raping children. A decision in that case is expected by late June.

The argument against the three-drug protocol is that if the initial anesthetic does not take hold, the other two drugs can cause excruciating pain. One of those drugs, a paralytic, would render the prisoner unable to express his discomfort.

The Kentucky inmates wanted the court to order a switch to a single drug, a barbiturate, that causes no pain and can be given in a large enough dose to cause death.

At the very least, they said, the state should be required to impose tighter controls on the three-drug process to ensure that the anesthetic is given properly.

Ginsburg, in her dissent, said her colleagues should have asked Kentucky courts to consider whether the state includes adequate safeguards to ensure a prisoner is unconscious and thus unlikely to suffer severe pain.

Stevens, while agreeing with Wednesday's outcome, said the decision would not end the debate over lethal injection.

"I am now convinced that this case will generate debate not only about the constitutionality of the three-drug protocol, and specifically about the justification for the use of the paralytic agent, pancuronium bromide, but also about the justification for the death penalty itself," Stevens said in an opinion in which he said for the first time that he believes the death penalty is unconstitutional.

Stevens suggested that states could spare themselves legal costs and delays in executions by eliminating the use of the paralytic.

Kentucky has had only one execution by lethal injection, and it did not present any obvious problems, both sides in the case agreed.

But executions elsewhere, in Florida and Ohio, took much longer than usual, with strong indications that the prisoners suffered severe pain in the process. Workers had trouble inserting the intravenous lines that are used to deliver the drugs.

Roberts said "a condemned prisoner cannot successfully challenge a state's method of execution merely by showing a slightly or marginally safer alternative."

He acknowledged that Wednesday's outcome would not prevent states from adopting a method of execution they consider more humane. Alito and Kennedy joined his opinion.

Justice Stephen Breyer concurred in the outcome, although he said he would evaluate the case under the same standard put forth by Ginsburg, that a means of execution may not create an "untoward, readily avoidable risk of inflicting severe and unnecessary pain."

Scalia and Thomas said Roberts' opinion did not go far enough in insulating states from challenges to their lethal injection procedures, which were instituted to make executions more humane. A "method of execution violates the Eighth Amendment only if it is deliberately designed to inflict pain," Thomas said.

Donald Verrilli, a veteran death penalty lawyer who argued the inmates' case, said he was disappointed in the decision, but hopeful about other challenges. "I think important issues remain after this decision," Verrilli said. "Records of administration of lethal injections in other states raise grave doubts about the reliability of those procedures."

The Rev. Pat Delahanty, head of the Kentucky Coalition to Abolish the Death Penalty, said the ruling wasn't a surprise.

"We never expected it to do more than maybe slow down executions in Kentucky or elsewhere," Delahanty said. "We're going to be facing some executions soon."

Wednesday's case involved two inmates, Ralph Baze and Thomas Clyde Bowling Jr., who were convicted of murder and sentenced to death by juries in Kentucky. Baze killed a sheriff and a deputy who were attempting to arrest him. Bowling shot and killed a couple and wounded their 2-year-old son outside their dry-cleaning business.

Fayette County Commonwealth Attorney Ray Larson, who prosecuted Bowling in 1992, said after the ruling: "Fact of the matter is, this lethal injection process is about as far from cruel and unusual as anything you can imagine. This is just another one of those things the anti-death penalty gang is throwing against the wall to see what sticks."

The case is Baze v. Ress, 07-5439.

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