A death row prisoner cracked a joke just moments before he was put to death for murdering a prison guard.
Rodney Berget was killed by lethal injection last night for the 2011 murder of prison guard Ronald 'R.J.' Johnson.
His execution was delayed for more than six hours as a last-ditch appeal to save him was considered by the US Supreme Court.
After it was rejected, the 56-year-old was taken to the execution chamber at South Dakota's state prison to be injected with a lethal cocktail of drugs.
When asked if he had any last words to say, he jokingly replied: "Sorry for the delay, I got caught in traffic."
Addressing his family and supporters, he also made a peace sign and said: "I love you and I'll meet you out there." He didn't apologise to the victim's family, who were present.
The murderer was then injected with a lethal cocktail of drugs at 7.25 pm. He reportedly, groaned, pushed out his chest and eventually drifted off, and was pronounced dead at 7.37pm.
Berget had already been serving a life sentence for attempted murder and kidnapping when he and another inmate, named Eric Robert, attacked Johnson with a pipe and plastic wrap in an attempt to escape from the South Dakota State Penitentiary in Sioux Falls in April 2011.
After beating the long-serving guard, who was nearing retirement, Robert put on Johnson's trousers, hat and jacket and pushed a cart loaded with two boxes, one with Berget inside, to the exit.
The pair succeeded in getting through one gate, but were stopped by another guard before they could flee.
Afterwards, Berget admitted to his role in the murder. However many objected to his killing on death row due to his mental status and the morality of the death sentence.
The 56-year-old had allegedly competed in South Dakota's Special Olympics state games as a boy in the early 1970s and Timothy Shriver, chairman of the board for Special Olympics International, was one of the people called on by America's top court to stop the execution.
In a letter, Shriver stated that Berget easily met the criteria set by a 2002 Supreme Court ruling that outlawed the execution of people with "mental retardation" on grounds such killings violated the Eighth Amendment's prohibition against cruel and unusual punishment.
However, his victim's family named his actions "evil", with Johnson's daughter, Toni Schafer, telling reporters after the execution: "Today was about choices. Berget had choices. He chose to be evil... to get what he wanted no matter what the cost. We choose as a family to be better."
Johnson's widow Lynette Johnson also compared her husband's "cruel and unusual punishment" to Berget's "peaceful" and "sterile" lethal injection.
She said: "They broke his neck, they severed fingers, broke his wrists, he didn't have the back of his head... that's cruel and unusual punishment."
Despite campaigns to save him, Berget reportedly had previously admitted that he deserved to die, telling a judge in 2011: "I knew what I was doing, and I continued to do it. I destroyed a family. I took away a father, a husband, a grandpa."
In addition, in 2016 he asked to withdraw the appeal against his death sentence, telling a judge he believed the death penalty would be overturned and he couldn't imagine spending "another 30 years in a cage doing a life sentence."
He was served his last meal on Sunday night: pancakes, waffles, breakfast sausage, scrambled eggs, French fries, Pepsi and Cherry Nibs licorice.
