WASHINGTON (Reuters) - The U.S. Constitution does not guarantee a prisoner sentenced to capital punishment “a painless death,” a divided Supreme Court said on Monday, paving the way for the execution of a convicted murderer who sought to die by lethal gas rather than lethal injection because of a rare medical condition.

FILE PHOTO: The building of the U.S. Supreme Court is pictured in Washington, U.S., March 18, 2019. REUTERS/Erin Scott/File Photo

Russell Bucklew, 50, had argued that lethal injection might inflict undue agony by rupturing blood-filled tumors on his face, head, neck and throat caused by a congenital condition called cavernous hemangioma in violation of the Constitution’s Eighth Amendment, which bars cruel and unusual punishment.

In a decision that exposed stark divisions among the justices on the death penalty, the court ruled 5-4 that Bucklew had failed to present enough evidence to pursue his request to be executed by lethal gas. The court’s five conservatives were in the majority and its four liberals dissented.

Referring to the history of capital punishment, conservative Justice Neil Gorsuch wrote for the court’s majority that “the Eighth Amendment does not guarantee a prisoner a painless death - something that, of course, isn’t guaranteed to many people, including most victims of capital crimes.”

“The state of Missouri and the victims of Russell Bucklew’s crimes have waited 23 long years for this just and lawful sentence to be carried out,” said a spokesman for Missouri Attorney General Eric Schmitt, a Republican. “With today’s ruling we are one step closer to justice.”

Bucklew’s lawyers did not immediately respond to a request for comment.

Monday’s ruling was in line with a 2015 decision in which the court rejected a challenge to Oklahoma’s method of execution by lethal injection. In that case, the court held that inmates challenging a method of execution must come up with an alternative option that was less painful.

Bucklew failed to show that lethal gas could be “readily implemented” as required under Supreme Court precedent, the court ruled. There also was no evidence that his chosen alternative, lethal gas, would be less painful, it concluded.

Gorsuch, appointed by President Donald Trump in 2017, noted that Bucklew is awaiting execution for crimes committed more than two decades ago.

“Yet since then, he has managed to secure delay through lawsuit after lawsuit,” Gorsuch wrote, echoing a view often expressed by death penalty advocates.

Fellow conservative Justice Samuel Alito said in 2015 that the legal challenge to Oklahoma’s method of execution case was part of a “guerilla war” against the death penalty.

Bucklew was convicted of the 1996 murder in southeastern Missouri of Michael Sanders, who was living with Bucklew’s former girlfriend Stephanie Ray at the time. Bucklew fatally shot Sanders at his trailer home, kidnapped and raped Ray, shot at Sanders’ 6-year-old son and wounded a police officer before being apprehended, according to court papers.

Bucklew’s appeal neither contested his guilt nor sought to avoid execution.

The case did not challenge the constitutionality of the death penalty itself. The court has barred the execution of juveniles and mentally disabled people, but there are no signs that its conservative majority is inclined to find capital punishment unconstitutional.

‘VIGILANCE AND CARE’

Liberal Justice Sonia Sotomayor took issue with Gorsuch, writing in a dissenting opinion that questions about legal tactics that lead to delays are “wholly irrelevant” to the case before the court.

“The majority seems to imply that this litigation has been no more than manipulation of the judicial process for the purpose of delaying Bucklew’s execution,” Sotomayor wrote.

When death row inmates seek last-minute stays of execution, courts should individual cases on their merits, Sotomayor said.

“Our jurisprudence must remain one of vigilance and care, not one of dismissiveness,” Sotomayor added.

Liberal Justice Stephen Breyer in another dissenting opinion repeated his assertion, first raised in the 2015 case, that if prisoners cannot be executed quickly without violating their rights “it may be that ... there simply is no constitutional way to implement the death penalty.”

In Missouri, execution is authorized using either injection or gas but the state in practice uses only lethal injection.

The high court last year blocked Bucklew’s execution on a 5-4 vote. The conservative justice who voted with the court’s four liberals to grant the stay, Anthony Kennedy, has since retired and was replaced by Trump’s appointee Brett Kavanaugh, who joined the conservative majority in Monday’s decision.

Other recent cases also illustrated the court’s differences over the death penalty. The court in February voted 5-4 to allow the execution of a Muslim convicted murderer after Alabama denied his request to have an imam present, saying he waited too long to file his lawsuit.

In an abrupt turnaround, the court last week blocked the execution of a convicted murderer whose request to have his Buddhist spiritual adviser present at the execution was denied by Texas..