Barring a last-minute reprieve, Ronnie Lee Gardner will tomorrow night be strapped into a chair, hooded and executed with a blast of gunfire from five rifles in the first death by firing squad to take place in the US in 14 years.

Gardner, 49, will be taken at midnight into a specially designed execution chamber in Utah state prison in Draper, Utah. A target will be placed over his heart, and then in the first minutes of Friday five unidentified law enforcement officers will line up in front of him with .30-calibre rifles. After Gardner is allowed to say his last words, they will be ordered to fire at the target.

Should the execution go ahead, it will be the first in Utah for over a decade and only the third time since the death penalty was restored in 1976 that a firing squad has been used. Both previous firing squads – the execution of Gary Gilmore in 1977 and that of John Taylor in 1996 – were used in Utah.

Other than Oklahoma, Utah is the only state in the US where the firing squad is listed as a possible execution method. Prisoners are allowed to choose between it and lethal injection, the cocktail of three drugs preferred by most other death penalty states.

In April, Gardner told a judge: "I would like the firing squad, please."

Gardner's death sentence relates to the shooting in 1985 of Michael Burdell, a defence lawyer. Gardner was in court in Salt Lake City, facing trial for murdering a barman called Melvyn Otterstrom, when he tried to escape from the courthouse and in the process shot and killed Burdell. He also shot a bailiff, Nick Kirk, who died from his injuries 10 years later.

Last week Gardner appeared before a five-member board of pardons to plead for them to commute the sentence.

He said that he was a changed man and that he wanted to devote his life to helping abused children.

"I'm really remorseful. I don't want to live for the sake of living. If I can help somebody and be a positive influence, that's what I want," he told the board.

But the panel noted that he did not make any claim of innocence over the killings, and ruled on Monday that execution was appropriate. The same day the Utah supreme court dismissed an appeal by Gardner's lawyers, who argued that there were mitigating circumstances for his behaviour including drug addiction as a youth, physical and sexual abuse and possible brain damage.

The lawyers have lodged a further appeal with the highest court in the country, the US supreme court. It is not yet known whether the court will agree to hear the petition.

The impending execution by firing squad has ignited a fierce debate within Utah about the death penalty in general and this method in particular.

Protesters will hold a prayer vigil outside Salt Lake City's Catholic cathedral and at the time of the execution on the steps of Utah's state capitol building.

Campaigners hope that the possibility of a firing squad being used will provoke revulsion in the American public and encourage states to speed up the pace of reform. Some 15 states have already dropped the death penalty and a further 12 are looking at it again.

The most notorious death by firing squad was that of Gilmore, who chose to be executed, refusing to make any legal attempt to prevent it, and also chose that method of dying. He had committed two murders in Utah.

The story of his life and death was told in novel form by Norman Mailer in The Executioner's Song, published two years after the execution.

Gilmore was strapped to a chair, and the five executioners were hidden in front of him by a curtain which had holes cut out of it for their rifle barrels.

Before they pulled the triggers, Gilmore famously exclaimed: "Let's do it!"

• This article was amended on 17 June 2010. In the original we refered to Norman Mailer's novel as The Execution Song. This has now been corrected.