After a last-minute stay of execution was refused, five anonymous marksmen bearing rifles took their places late on Thursday in a prison room to carry out the request of death row inmate Ronnie Lee Gardner: execution by firing squad.
Gardner wouldn't have seen the law enforcement officers who volunteered to carry out the death sentence. He would have been bathed in light, while they remained hidden in darkness some 20 feet away.
A target was placed over his heart and a hood over his head before the five men opened fire.
He was pronounced dead at 0020 local time (0620 GMT).
None of the firing squad will ever know for sure if he fired a lethal shot. One gun was loaded with a dummy - probably wax - bullet, which is said to deliver the same recoil as a live round.
Gardner, 49, was sentenced to death in 1985, after fatally shooting lawyer Michael Burdell and severely wounding a bailiff Nick Kirk in an escape attempt from court. At the time, he was facing a murder charge in the case of the shooting of bartender Melvyn Otterstrom.
Although death by firing squad has been outlawed in Utah since 2004, the law does not apply to those convicted before that date, so Gardner was allowed to choose it as the method of his execution.
Gary DeLand, executive director of Utah's corrections agency from 1985 to 1992, knew Gardner during the early years of his imprisonment. He says he was not surprised by this request.
"He was a particularly violent man. He was kept away from other inmates. He was the kind of person who would harm others for the sport of it, and enjoyed causing trouble.
"We don't know why Gardner chose this method but one prisoner who had chosen the firing squad basically said if he was going to die, he wanted someone to have to clean up the mess."
Executions by firing squad are rare in the US - only two people have been put to death this way since 1977.
Mr DeLand, who oversaw executions by lethal injection and planned one execution by firing squad (which had to be abandoned at the last minute) wrote a prison manual in 1986 setting out a plan.
"I have been told the manual is still at the Utah prison and has been dusted down," he says.
According to Mr DeLand's proposal, Gardner would have been taken to a holding cell 24-48 hours ahead of execution. There a prisoner is watched continually by rotating teams of prison staff, to ensure he doesn't try to take his own life.
"That's why we called it the 'Death Watch cell'," he says.
Only a few people would have been allowed to enter - lawyers, for example, working until the last minute to secure a stay of execution.
The identities of the marksmen - local law enforcement officers who have volunteered their services - will be protected forever.
"They will probably have practised for some time in the chamber to ensure they fire in unison. We want to hear one single noise - not, bang, bang, bang, bang, bang," says Mr DeLand. There is likely to be a standby executioner in case one loses his nerve.
The marksmen, along with members of staff who contributed to the planning of the execution, will be given a commemorative Gardner coin.
It was Mr DeLand who introduced the tradition of handing out commemorative badges for "service beyond their ordinary daily duties". Apparently, this time, staff preferred something "a bit more modern".
Throwback to earlier time
His case has attracted much national and international interest because the method has been vilified by many as an anachronistic form of Wild West-style justice.
According to the Death Penalty Information Centre, the Supreme Court gave Utah permission to use the firing squad as a method of execution in 1879.
"This is clearly a throwback to an earlier time, and people wonder, how can we still be doing that?" Richard Dieter, executive director of the centre, told CBS news recently.
The last person to have been executed by firing squad was John Albert Taylor in 1996, who said he chose the method to embarrass the state.
But Gary DeLand says he doesn't know why execution by firing squad generates so much interest. "An execution is an execution," he said. "I guess it's just morbid curiosity."
The families of Gardner's victims are divided over the execution.
Nick Kirk's widow VelDean said before the execution that it would come as a relief, and she was planning to be a witness.
Family and friends of Michael Burdell were quoted as saying that the execution would simply be a victory for the violence that the lawyer sought to curb. Donna Nu, his fiance at the time, told the BBC World Service in April that we should have "gone past eye for an eye, tooth for a tooth".
Asked about Gardner's method of execution, she said he may have chosen it "partially to make the point how barbaric it is. Firing squad makes it more real what's happening than lethal injection does."
Historians say the method stems from 19th Century doctrine of the state's predominant Mormon religion.
In a recent article in the Salt Lake Tribune, journalist Peggy Fletcher Stack traces the history of the firing squad in the state and reports that according to some people in Utah, one reason why the execution technique remained an option was because of the notion of "blood atonement."
She explains that the term refers to an "arcane LDS (Church of Jesus Christ of Latter-day Saints, or Mormons) belief that a murderer must shed his own blood - literally - to be forgiven by God."
Ahead of the execution, the LDS released a statement saying that blood atonement was not a doctrine of the Church.
Prison officials have said that counsellors will be on hand to talk to members of staff, should they need it, after Gardner's execution. Few will have experienced what those five men will go through.
But unnamed officers who took part in the last execution by firing squad this week described their experiences to the Salt Lake Tribune.
One described it as an "assignment, nothing more than getting an order to do something like kicking in a door to serve a warrant".
Another likened John Albert Taylor's execution to "returning a defective product to the manufacturer". And one said he "had issues about shooting a guy strapped in a seat, helpless. But the state had ordered us to do this and we had a job to do. I don't regret doing it, but I would never do it again."