The extraordinary gesture from the family of man killed by Kenneth Williams, who is due to be executed in Arkansas

The family of slain man Michael Greenwood have offered to pay for Kenneth Williams' (pictured) family to see him before he is executed. Photo / AP

Arkansas' execution spree continues when Kenneth Williams becomes the fourth inmate in a little more than a week to be put to death.

Before some of the last remaining vials of the US state's dwindling stock of deadly drugs are pumped into his veins, Williams will receive a visit from his daughter and granddaughter.

But what is extraordinary about this reunion is it's being paid for by the family of one of William's victims.

It's an extraordinary gesture many of us might find difficult to comprehend, but Kayla Greenwood said they had forgiven Williams for the death of her father, who was killed in 1999 when the on-the run killer caused a car crash.

Others are less willing to forgive. Genie Boren's husband Carl was killed by Williams when he broke into the couple's home. She says, "people have to be punished for the things they've done."

In 1998, Williams was sentenced to life without parole after he shot dead Dominique Hurd and almost killed her friend Peter Robertson.

A year later he escaped from the Cummins Unit prison in Varner, south of the city of Pine Bluffs. The Cummins Unit is the facility where Arkansas conducts its execution.

Williams managed to evade the guards by hiding away in a vat of pig slop as it was ferried from the prison kitchen to a feeding bay, then sneaked along a tree line to escape.

Just a few kilometres from the prison, and still in Varner, he stumbled across Carl Boren tending his garden.

The escapee shot and killed Mr Boren before stealing some guns and making a run for it. It was while being chased by police that his car ploughed into Mr Greenwood's vehicle killing him.

In 2000, he was sentenced to death for Mr Boren's killing.

Mr Greenwood's daughter, Kayla, told the Springfield News-Leader that she learned a few days ago that Williams had a 21-year-old daughter, Jasmine, whom he hasn't seen for 17 years and a three-year-old granddaughter he'd never met.

Ms Greenwood said her mother bought plane tickets for Williams' daughter and granddaughter to fly from Washington state to Arkansas so they could see him on Wednesday, a day before his execution.

Jack Harold Jones (L) and Marcel W. Williams (R) were executed by the state of Arkansas this week. Photo / AP

"I told him we forgive him and where I stood on it," said Ms Greenwood, who sent a message to Williams through his attorney.

"When he found out that we are bringing his daughter and granddaughter to see him and that my mom and dad bought the tickets, he was crying to the attorney."

Members of Mr Greenwood's family had urged clemency for Williams. But family members of Mr Boren told the Arkansas Parole Board that the execution should go forward.

"We've been waiting a long, long time for this. He did a wrong, his jury of peers gave him a death sentence," Mrs Boren told local TV station Fox 16.

On Tuesday, Jack Jones became the second of four death row inmates to be executed in the last week. Arkansas is in the midst of a rush on executions as its store of lethal injection drugs nears expiry at the end of the month.

Like Mrs Boren, the husband of the woman raped and murdered by Jones has also not found the space to forgive her killer.

James Phillips said he had no qualms about the execution and has hit out at those who called for mercy.

"It don't matter if they suffered a little bit as far as I'm concerned because my wife suffered big time," he told the BBC.

"She was sexually abused in every way possible," said Mr Phillips.

"As she was suffering he took a cord of a coffee pot and strangled her and I don't know how much meaner a man can get to do something like that."

Williams is due to be killed at 9pm Thursday, Arkansas time. He will be executed just a few kilometres from where he killed Mr Boren.