"The U.S. Supreme Court refused Wednesday to stop the execution of Richard Glossip, whose case drew a call for mercy from Pope Francis. The justices weighed in just minutes before Glossip was scheduled to be put to death for the 1997 murder of his boss, Barry Van Treese. Glossip, whose supporters include "Dead Man Walking" nun Helen Prejean and actress Susan Sarandon, insists he did not orchestrate the brutal killing. In a letter to Oklahoma Gov. Mary Fallin dated Sept. 21, the pope's representative asked her to commute Glossip's death sentence, saying that would "give clearer witness to the value and dignity of every person's life." A spokeswoman for Fallin said she does not have the authority to commute the sentence...Glossip's execution has been stayed three times before, including last winter when the Supreme Court agreed to hear his challenge to Oklahoma's lethal-injection drugs. The justices eventually upheld the state's protocol. Just two weeks ago, Glossip was hours away from being escorted to the execution chamber when a state appeals court halted the process so it could consider his claim that new evidence shows he is innocent. Glossip's conviction hinged largely on the testimony of the man who actually carried out the 1997 bludgeoning murder of his boss. That man, Justin Sneed, is serving a life sentence. The defense says it has witnesses who back up their claim that Sneed acted alone, and that the state has tried to intimidate those witnesses by hitting them with probation violations."