A man on death row in Mississippi was executed on Wednesday evening, nearly five decades after he abducted and murdered a bank loan officer’s wife  in a brutal ransom plot. Richard Gerald Jordan, a 79-year-old Vietnam veteran with post-traumatic stress disorder, was sentenced to death in 1976 for killing and abducting Edwina Marter. His final appeals were dismissed without comment by the US Supreme Court.

He died by lethal injection at the Mississippi State Penitentiary in Parchman after giving an emotional statement to his victim’s relatives and asking his wife for forgiveness. Jordan lay on the gurney and took several deep breaths before becoming motionless after the execution began at 6pm. The time of death was recorded as 6:16pm.

When given an opportunity to deliver a final statement on Wednesday, he said: “First I would like to thank everyone for a humane way of doing this. I want to apologise to the victim’s family.” He also thanked his solicitors and his wife and asked for forgiveness. His last words were: “I will see you on the other side, all of you.”

Jordan’s wife Marsha Jordan witnessed the execution, along with his solicitor Krissy Nobile and a spiritual adviser, the Rev Tim Murphy. His wife and solicitor dabbed their eyes several times.

Jordan’s execution concluded a decades-long legal process that included four trials and numerous appeals. On Monday, the Supreme Court turned down a petition that argued he was denied due process rights.

“He was never given what for a long time the law has entitled him to, which is a mental health professional that is independent of the prosecution and can assist his defence,” said solicitor Nobile, who represented Jordan. “Because of that his jury never got to hear about his Vietnam experiences.”

A recent petition asking Gov Tate Reeves for clemency echoed Nobile’s claim. It said Jordan suffered severe PTSD after serving three back-to-back tours, which could have been a factor in his offence.

“His war service, his war trauma, was considered not relevant in his murder trial,” said Franklin Rosenblatt, president of the National Institute of Military Justice, who wrote the petition on Jordan’s behalf. “We know so much more than we did 10 years ago, and certainly during Vietnam, about the effect of war trauma on the brain and how that affects ongoing behaviours.”

The victim’s son, Eric Marter, said he does not accept that argument: “I know what he did. He wanted money, and he couldn’t take her with him. And he did what he did.”