Five sharpshooters fired bullets through the heart of a double murderer in what was billed as a bloody throwback to Old West-style justice.
Ronnie Lee Gardner, 49, was killed by a firing squad in an unusual Utah execution.
Gardner, convicted of two murders, chose the method over lethal injection.
Execution by firing squad was outlawed by Utah in 2004 but the ban was not retroactive.
Five sharpshooters fired bullets through the heart of double murderer Ronnie Lee Gardner on Friday, making him the first U.S. prisoner in 14 years to be executed by firing squad.
Shackled to a chair and with a black hood covering his head, Gardner, 49, was put to death just after midnight in a brightly lit execution chamber at Utah State Prison.
Asked if he had any last words, Gardner, who had been on death row for 25 years, replied: "I do not. No."
Utah Department of Corrections director Thomas Patterson told reporters Gardner was pronounced dead two minutes after being shot.
"This is an unusual task but one we have done professionally," Patterson said. "It has been done with absolute dignity and reverence for human life.
Gardner's gruesome death was billed as a bloody throwback to Old West-style justice, the first execution of its kind in the United States for more than a decade and possibly the last ever. Execution by firing squad was outlawed by Utah in 2004 but the ban was not retroactive, meaning Gardner was able to choose the method instead of lethal injection during a hearing in April.
But there was an unmistakably 21st century twist to his final minutes when Utah Attorney General Mark Shurtleff used micro-blogging site Twitter to announce he had given the final approval for the execution.
"I just gave the go-ahead to Corrections Department to proceed with Gardner's execution," Shurtleff tweeted shortly before Gardner was shot. "May God grant him the mercy he denied his victims."
Gardner had spent 25 years on death row for gunning down an attorney in a failed bid to escape from a court room in 1985 during a murder trial. His case had renewed debate about use of the death penalty in the United States and divided family and friends of his victims.
Loved ones of lawyer Michael Burdell, shot dead by Gardner in his botched escape attempt, have said they were against his execution because Burdell opposed the death penalty.
"Michael was a gentle soul. And he loved people and he loved life. And he would not have wanted Ronnie Lee to be killed, especially in his name," Donna Nu, Burdell's fiance told CNN earlier Thursday.
"I think that we as a human race -- all the brilliant minds we have on this planet -- we could come up maybe with something better."
However the family of a court security guard shot and wounded by Gardner testified that they wanted the execution to proceed, saying the now-deceased Nick Kirk had suffered years of mental and physical anguish.
"He has never shown any compassion for any of his victims. So why does he deserve any compassion?" Kirk's daughter Tami Stewart told the parole hearing.
Critics of the death penalty have condemned Gardner's execution as "barbaric."
"It's difficult to understand the issue of how can we still be engaged in this form of barbarism," Elisabeth Semel, director of the Death Penalty Clinic at the University of California, Berkeley School of Law said.
"The firing squad is so anachronistic... the only way to understand it is to understand the history of the death penalty in the US. It's different.
"It has its origin in Europe but it has a very American flavor. This is not by way of justification but by way of explanation."
Semel believes Gardner's execution is linked to Utah's Mormon roots where "the idea of blood atonement is very meaningful."
"The idea of if you're committing a murder, the only way that you can genuinely demonstrate a remorse and being adequately punished is by showing your own blood," she said.
A member of the last firing squad used in Utah, which executed a man who had been sentenced to death for raping and murdering an 11-year-old girl in 1989, gave an insight into the process in an interview with CNN.
"It was anti-climactic," he told CNN. "I've shot squirrels I've felt worse about. There's just some people we need to kick off the planet."