In 2004, Utah lawmakers made lethal injection available in death penalty cases but inmates condemned before then were given the choice of a firing squad. In April, a judge asked Gardner for his preference.
"I would like the firing squad, please," he politely replied.
Execution by firing squad, long associated with military tribunals, has been criticized by human rights groups as archaic. In fact, the guillotine and the electric chair were introduced because they were seen as more humane than facing a firing squad.
But some experts say the firing squad isn't as barbaric as one might think.
"People think lethal injection is more human because it's related to medicine and doctors and a peaceful way of death, but in reality, it's not," said Deborah Denno from Fordham University. "It is an irony isn't it that the method we think is most barbaric to our perception and in our history is in fact the method that is most humane."
Modern firing squad executions in the U.S. have gone smoothly, but it was not unusual in the past for several rounds to strike the prisoner without killing him. In such cases, a final shot was fired at close range to put the inmate out of his misery. Witnesses in Gardner's execution were warned that he would be shot again if the first round of shots didn't kill him.
"No man who has ever lived on this earth could survive four rounds from a .30-30 rifle to the chest," Gary DeLand, former head of corrections in Utah, told ABCNews.com. "You can almost almost shut your eyes and hit him from that distance."
Despite the assertions of Gardner's lawyers, some people doubted that the man could ever be reformed.
Tami Stewart's father, George "Nick" Kirk, was a bailiff who was shot and wounded in Gardner's botched escape. Kirk suffered chronic health problems until his death in 1995. He became frustrated by the lack of justice Gardner's years of appeals afforded him, Stewart told the Associated Press.
She's not happy about Gardner's death, she said, but believes it brings her family some closure.
"I think at that moment, he will feel that fear that his victims felt," Stewart said.
But Burdell's father, Joseph Burdell Jr., said Gardner's expressed desire to help troubled kids was evidence that some transformation had occurred.
"I understand that he wants to apologize. I think it would be difficult for him," he told the Associated Press by phone Tuesday from his Cary, N.C., home. "Twenty-five years is a long time. He's not the same man."
Shortly after midnight Friday, Shurtleff, the state attorney general, took out his iPhone and opened the TwitBird Twitter application to annouce by tweet that he "just gave the go ahead to Corrections Director to proceed with Gardner's execution. May God grant him the mercy he denied his victims."