A DEATH row killer's chilling final words after receiving the lethal injection have been released.

Rodney Berget, 56, from South Dakota, asked "Is it supposed to feel like that?" after receiving the needle, before groaning, saying "ahhh" and then starting to snore.

The complete transcript then describes how at 7.37pm, 12 minutes after receiving the barbiturate pentobarbital injection, the convicted murderer was pronounced dead.

Berget was put to death for the murder of prison guard Ronald “R.J.” Johnson in 2011 during a botched prison escape.

His execution had been delayed for hours while the US Supreme Court considered a last-minute legal bid to block it.

As the final process begins the warden in charge of the execution tells Berget:

"Do you have any last words? Now is that time."

Berget responds with a joke, saying: “Sorry for the delay, I got caught in traffic.”

His voice is described to shake as he thanks people for their support and made a peace sign: "But seriously, I want to thank everybody that was there for me. I love you all."

He was the second member of his family to receive the death penalty.

His older brother, Roger, was executed in Oklahoma in 2000 for killing a man to steal his car.

Johnson's widow, Lynette Johnson, who witnessed the execution, said her husband experienced "cruel and unusual punishment" but Berget's lethal injection was "peaceful" and "sterile."

She said: "What's embedded in my mind is the crime scene.

“Ron laid in a pool of blood. His blood was all over that crime scene.

Johnson turned 63 on the day that he was killed, and he was nearing the end of a nearly 24-year career as a guard.

Berget had been serving a life sentence for attempted murder and kidnapping when he and another inmate, Eric Robert, attacked the long-serving guard on April 12, 2011.

It happened in a part of the prison known as Pheasantland Industries where inmates work on upholstery, signs, furniture and other projects.

After Johnson was beaten, Robert put on Johnson's pants, hat and jacket and pushed a cart loaded with two boxes, one with Berget inside, toward the exits.

They made it outside one gate but were stopped by another guard before they could complete their escape through a second gate.

Berget admitted to his role in the murder.

His mental status and death penalty eligibility played a role in court delays.

Berget in 2016 appealed his death sentence, but later asked to withdraw the appeal against his lawyers' advice.

He wrote to a judge saying he thought the death penalty would be overturned and that he couldn't imagine spending "another 30 years in a cage doing a life sentence."