DEATH row’s oldest inmate left behind an eerie plea with his final words before being executed by lethal injection.

In Tennessee, 75-year-old Oscar Smith faced execution on Thursday morning for the 1989 killings of his former wife and her two teenage sons, marking the state’s first execution since 2020.

With his final words, Smith insisted that he was innocent and begged for the justice system to be reformed.

He said: “Somebody needs to tell the governor the justice system doesn’t work.”

Refuting his conviction one final time, Smith said: “I didn’t kill her.”

He was pronounced dead at 10:47am on Thursday after receiving a lethal dose of the drug pentobarbital at Riverbend Maximum Security Institution.

The Sun recently interviewed a former executioner who witnessed a prisoner’s head catch fire, as well as a pastor who has provided companionship to numerous inmates during their last moments.

Smith was convicted of fatally stabbing and shooting his estranged wife Judith Smith, 13-year-old Jason Burnett and 16-year-old Chad Burnett.

He murdered them at the home in Nashville, Tennessee, on October 1, 1989.

Sentenced to death in July 1990, Smith spent almost 35 years on death row, and was its oldest inmate in the US.

A county judge refused a motion to revisit the case in 2022, even though new evidence suggested that DNA from another individual was discovered on one of the weapons used in the crime.

The judge ruled that the evidence of Smith’s guilt was overwhelming and that the new information did not change that.

Two of Smith’s colleagues told the original trial that he asked them to kill Judith.

He also had a history of violence and threats against the family.

Further clinching the conviction was the fact that Smith took out insurance policies on all three of his victims.

The court also heard that one of the teen victims could be heard screaming “Frank, no!” in the background of a 911 call at the time of the murders.

Frank is Smith’s middle name, and the one he used regularly.

After Smith had been confirmed dead, Judith’s two siblings said they still miss the three victims, all these years later.

Her sister, Terri Osborne, said the deaths are a reminder of the dangers of domestic violence.

She said: “We know it is an incredibly hard thing to do to leave a spouse who is abusing, but pray that this case becomes a call to action, encouraging those in danger to seek help before it’s too late.”

Smith’s execution was the first in Tennessee since 2020, and he chose the lethal injection – a cocktail of three drugs.

He could alternatively have chosen to be killed in the electric chair.

There has been significant controversy around the method in recent years – with Justice Sonia Sotomayor of the Supreme Court describing it as “the chemical equivalent of being burned at the stake”.

In March, a double murderer called Brad Sigmon became the first person in the US to be executed by firing squad in 15 years.

He reportedly kept breathing after being shot three times in the chest.

Three special bullets were shot at his heart by three volunteer riflemen at the South Carolina Department of Corrections in Columbia.

Sigmon, 67, was convicted of beating to death with a baseball bat his ex-girlfriend’s parents, David and Gladys Larke, at their Taylors home in 2001.