(CNN) -- The U.S. Supreme Court rejected a request Thursday to temporarily stay the execution of death row inmate Ronnie Lee Gardner, who is set to die before a Utah firing squad early Friday.
The Supreme Court's rejection ended the last legal maneuver for Gardner, 49, who is scheduled to face execution shortly after midnight Friday (2 a.m. ET) for the shooting death of attorney Michael Burdell during a botched escape attempt from custody in 1985 at a Salt Lake City, Utah, courthouse. He would be only the third person to die by firing squad in the United States in 33 years.
Utah Gov. Gary Herbert rejected two appeals by Gardner's attorneys to stop the execution, saying Gardner had every chance to present his case.
"Upon careful review, there is nothing in the materials provided this morning that has not already been considered and decided by the Board of Pardons and Parole or numerous courts," Herbert wrote in a letter to the attorneys rejecting the first appeal. "Mr. Gardner has had a full and fair opportunity to have his case considered by numerous tribunals."
Among the claims Gardner raised in his appeals is that he has been a death row inmate too long. "He asserts that executing him now, after nearly 25 years on death row in Utah, so lacks retributive or deterrent value that it violates the Eighth Amendment," Andrew Parnes, Gardner's lawyer, told the high court. He did not return phone calls from CNN seeking comment.
A federal judge late Tuesday refused to block the execution, after Gardner claimed the procedures related to a two-day commutation hearing held by the state Board of Pardons and Parole last week violated his civil rights. The parole board Monday refused to commute Gardner's sentence to life in prison, and the Utah Supreme Court on Tuesday also denied his request for a stay.
Gardner testified before the board he is a changed man, and his sentence should be commuted.
That was the issue before the 10th Circuit U.S. Court of Appeals in Denver, which concluded the clemency hearings were conducted fairly and did not violate the inmate's civil rights.
"There is no merit to the claims asserted in the underlying [civil rights claim] challenging the procedures followed in Mr. Gardner's state clemency proceeding," wrote the three-judge panel. "In light of that fundamental deficiency, Mr. Gardner's associated application for a stay of his execution was also meritless."
He is set to become the third person to die by rifle fire, all in Utah, since the Supreme Court restored the death penalty in 1976. He had a long history of escapes and was slipped a gun before he fatally shot Burdell on April 2, 1985. He was at the courthouse for a pre-trial hearing in the 1984 slaying of Melvyn Otterstrom, who was killed at the Salt Lake City bar where he was working to earn extra money.
The execution will be held at the Utah State Prison in Draper, about 20 miles south of Salt Lake City.
Corrections officials announced Gardner had consumed his last meal Tuesday night at 6:30 p.m., and has elected to fast prior to the anticipated execution. His dinner included steak, lobster, 7-Up, apple pie and vanilla ice cream.
As he awaited execution, Gardner watched the "Lord of the Rings" trilogy in an observational cell and read a novel by David Baldacci entitled "Divine Justice," said Utah Department of Corrections spokesman Steve Gehrke.
In the hours before the scheduled execution, Gardner met with a bishop from the Church of Jesus Christ of Latter-day Saints, Gehrke said.
During the commutation hearing, parole board members heard testimony regarding Gardner's childhood, which was punctuated by poverty, abuse and neglect. Parnes maintained that jurors in the Burdell trial never heard this evidence -- and presented affidavits from jurors who said it might have persuaded them to decide against the death penalty.
Life in prison without the possibility of parole was not an option for jurors at the time, and Parnes said it was suggested to the jury that Gardner might be released from prison at some point if he were given a life sentence.
Gardner pleaded guilty to second-degree murder in Otterstrom's death, and jurors were not told of a judge's recommendation in that case that he not be released from prison, Parnes said.
Utah is the only state that uses the firing squad as a current execution method. Oklahoma allows it only if lethal injection and electrocution are ruled unconstitutional. Forty of Utah's 49 executions in the last 160 years or so have been done this way, according to the Death Penalty Information Center.
State lawmakers made lethal injection the default capital punishment in 2004, but at least three inmates who already had chosen the firing squad were grandfathered in under the new law.
Five anonymous marksmen will use matching .30-caliber rifles, standing behind a wall cut with five gunports. One of the rifles will be an "ineffective" round, similar to a blank, which delivers the same recoil as a live round. That ensures none of the riflemen will know who delivered the fatal shot.
The marksmen fire from a distance of 25 feet. The inmate is blindfolded, strapped to a chair and a target pinned to his chest.
CNN's Ashley Hayes contributed to this report.