The son of an Alabama father of seven who was fatally shot while taking money out of an ATM says the family has "long forgiven" the death row inmate set to be executed Thursday for the murder.

Keith Edmund Gavin, 64, will become the third inmate executed in Alabama this year and the 10th in the nation if his lethal injection proceeds as scheduled on Thursday. He was convicted in the 1998 death of 68-year-old William Clinton Clayton, Jr., who was a great dad and a "gentle giant," his son, Matt Joseph Claying, told USA TODAY this week.

"I don't think anyone anticipated that his life would end this way," said Matt Clayton, who was 28 when his father was gunned down. "Certainly not his family ... It was quite shocking."

As Gavin's execution nears, USA TODAY is looking back at the crime and who William Clayton was.

Who was William Clinton Clayton, Jr.?

Clayton, who went by Bill, was a native of Clay, Alabama, and a contract courier for Corporate Express Delivery Systems, Inc.

At 6 feet, 6 inches tall and 280 pounds, Bill was "quite a large man" but also "a bit of a gentle giant," Matt Clayton recalled.

One thing Clayton will always remember about his dad is how hard he worked to provide for his seven children and wife of 38 years

"He worked about 14 hours a day, usually from 5 o'clock in the morning until 8 o'clock at night, Monday through Friday," Clayton said. "He would work about a 10-hour day on Saturday. Really work was all that the man knew."

After William Clayton did not graduate high school, he worked many unskilled professions, including custodial work, railroad work and several driving-related jobs, according to his son. He also had learning disabilities and was "a simple man."

Matt Clayton said his mother, who is now 94 years old, lives independently and is "very healthy and very vibrant."

"It's truly been a blessing to have her around for so much of my life, particularly since my father was gone at a younger age," he said.

What happened to Bill Clayton?

On March 6, 1998, Clayton was gearing up to take his wife of 38 years out to dinner. He was driving in his Corporate Express Delivery Systems van when he stopped at Regions Bank in downtown Centre to grab some money from the ATM for the couple's date night.

Meanwhile, Gavin had driven to the region from his hometown of Chicago with his cousin, Dewayne Meeks, to track down a woman Gavin had met in the past. Gavin and Meeks arrived in downtown Centre just as Clayton went to the ATM, according to court documents obtained by USA TODAY.

While the men were stopped at an intersection near Regions Bank, Meeks testified in court that Gavin got out of the car, walked up to the driver's side of Clayton's van and fired two shots. Meeks then drove off in his car, while Gavin got in Clayton's van − with Clayton still in it and bleeding out − and followed Meeks, court records say.

Danny Smith, an investigator with the local district attorney’s office, testified that he was in the area when he heard about a shooting over the radio and that both the shooter and victim were in a white van. Soon after that, Smith spotted the van speeding and driving erratically.

A pursuit ensued for several minutes before the van abruptly stopped and the driver jumped out and fired a shot at Smith before running into nearby woods, Smith testified. Smith immediately went to the van to check on Clayton, who was "barely alive" and died shortly after at a hospital, court records say.

Gavin was convicted of capital murder on Nov. 6, 1999, largely based on his Meeks' eyewitness testimony.

Keith Edmund Gavin has shown a 'lack of remorse'

Gavin has always maintained that he did not shoot Clayton and has filed numerous appeals of his conviction and death sentence.

And while the family has forgiven Gavin, Matt Clayton said he does feel that he's shown a "lack of remorse for taking the lives of his victims."

He cited Gavin's upbringing as part of why the family has forgiven him, saying he was "born in poverty and ... raised in a crime-infested environment."

"As we look at the unfortunate events unfold during the course of his life, I think that Mr. Gavin may have been indoctrinated into gang violence at an early age, as many young people are who lacked strong male role models," he said. 

He added that "it's truly sad to think about this person."

"He's facing the end of his life and most of his life has been spent incarcerated," he said. "A significant portion of his life has been spent on death row."

Matt Clayton said he is glad Gavin received appropriate legal representation and was "given the benefit of the criminal justice system for the series of appeals."

"The criminal justice system is there for everyone and I'm certainly pleased that all citizens are well-served," according to Matt Clayton.

Clayton, who is now 54, said he will be attending Gavin's execution at the Holman Correctional Facility in Atmore, Alabama, to "represent his family" and recognize the efforts by the state officials who "brought Mr. Gavin to justice."

"No one wants to view an execution, so let's be clear about that," he said. "However, I cannot choose to not attend given the work that has been put forth."