Washington (CNN) -- A Utah death row inmate who would become only the third person to die by firing squad in the United States in 33 years appealed to the Supreme Court on Wednesday, seeking a last-minute stay of execution.

Ronnie Lee Gardner's lawyers filed the first of what are expected to be several appeals to the justices. He is scheduled to be put to death early Friday for the shooting death of attorney Michael Burdell during a botched escape attempt from custody in 1985 at a Salt Lake City, Utah, courthouse.

Among the claims the 49-year-old prisoner raises 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.

Executioner: Death by firing squad is '100 percent justice'

Gardner's lawyers have launched an aggressive scramble in state and federal courts, as well as the Utah Board of Pardons and Parole, to at least postpone the execution.

A federal judge late Tuesday refused to block it, after Gardner claimed the procedures related to a two-day commutation hearing held by the board last week violated his civil rights. Parnes had argued the clemency hearing was not fair and impartial because representatives from the Utah attorney general's office were both presenting the state's case at the hearing and advising the board. Attorneys representing the state agency said safeguards were in place to prevent a conflict of interest.

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. He claims he is a changed man, and should not be executed for his crimes.

Gardner 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 is set for just after midnight (2 a.m. ET) 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, and vanilla ice cream.

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.

Lethal injection remains by far the most-used execution method in the United States and is the primary or only option in the 35 states with capital punishment. Nine states still use electrocution, five states have the gas chamber, and two -- Washington and New Hampshire -- would hang condemned inmates as an alternate method.

The Supreme Court case is Gardner v. Utah (09-11378).

CNN's Ashley Hayes contributed to this report.