KNOXVILLE, Tenn. — When Hugh and Mary Newsom embraced their burned son's form in a body bag, they made a pledge: they would get the man responsible for his torture, rape and murder. 

It took 12 years, hundreds of trips to court and eight criminal trials, but they said they have now fulfilled that promise to their son.

Now, the couple is sharing the rarely-told story from behind the scenes: the details of their pleas to prosecutors, their face-to-face meeting with a convicted murderer and their feelings of relief and victory at the latest--and last--guilty verdict. 

In August, a Knox County jury found Eric Boyd guilty of 36 counts of carjacking, robbery, kidnapping, rape and murder. Boyd is the fifth suspect convicted in the Christian-Newsom case, one of the worst crimes in county history. 

RELATED: Boyd trial, Day 6 | Eric Boyd guilty of first-degree felony murder, kidnapping & rape

Channon Christian, 21, and Chris Newsom, 23, were kissing in the parking lot of a Knoxville apartment complex in January 2007. They planned to go to dinner and then a friend's house for a party. 

Channon Christian and Chris Newsom
Channon Christian and Chris Newsom

Instead, the young couple was carjacked, taken to a home on Chipman Street in North Knoxville, raped and then killed. 

Within weeks, five suspects were charged in relation to the crime, but only four were ever tried on murder charges. 

RELATED: 12 years later, the final suspect in the Christian-Newsom torture-slayings is set for trial

The Newsoms have long believed Eric Boyd, the remaining suspect, was responsible for their son's rape and murder. Prosecutors waited more than a decade before bringing state charges against Boyd, who was initially found guilty of crimes after the fact in federal court. 

KNS Eric Boyd Trial Aug. 12, 2019
Eric Boyd, left, during his trial for the 2007 murders of Channon Christian and Christopher Newsom in Knox County Criminal Court on Monday, August 12, 2019.
Brianna Paciorka/News Sentinel

In many ways, the Newsoms said it was their persistence that eventually convinced prosecutors to bring Boyd's case to a grand jury. 

They describe their work as frustrating as officials declined again and again to prosecute Boyd. The couple assembled piles of piles of documents, researched similar cases and even met with one of their son's killers face-to-face. 

"We thought we were going to be friends"

The letter from the Riverbend Correctional Institute arrived in the fall of 2015: Letalvis Cobbins had agreed to meet with the Newsoms.  

"We weren't afraid," Mary Newsom said. "We were hoping he might be able to help us." 

Hugh Newsom said the couple made it clear they wanted Cobbins to turn on Boyd and testify that the fifth suspect took part in the carjacking and kidnapping of their son, Chris. 

He agreed--at least at first. 

Letalvis Cobbins
Letalvis Cobbins testifying in his own defense in his 2009 trial.

"Cobbins was friendly," Hugh Newsom said. "He talked to us without any hesitations." 

The Newsoms told him they couldn't promise time off his sentence, but could try to help him gain access to academic courses behind bars. They spoke to the warden on his behalf.

It was the beginning of a brief friendship between Cobbins and parents of the man he was convicted of killing. The inmate even sent Mary Newsom a gift with a bible verse. 

"I hung it on the wall for a little while," Mary Newsom said. "Then when he changed his mind, I took it down." 

The Newsoms describe Cobbins backing out of his agreement to testify against Boyd as an emotional body blow.

Cobbins reneged on the verbal agreement in December 2015 during a meeting at the Northwest Correctional Complex in Tiptonville, Tenn. with the Newsoms and officials from the Knox County District Attorney General's office. 

As the Newsoms made the nearly six hour drive to that prison, they had high hopes they were nearing a breakthrough in their quest to bring Boyd to trial. 

"I kept thinking 'Well, this may be a Christmas miracle,'" Mary Newsom said. "That's what I was hoping for." 

Instead, they drove back to Knoxville in defeat. 

"We were of the mindset that we were not going to give up." 

After the Cobbins setback, the Newsoms took stacks of evidence back to the Attorney General's office and again tried to convince prosecutors to bring a circumstantial case against Boyd, to no avail. 

"To us it seemed like there was plenty of evidence. It seemed like a fifth grader could've figured it out," Mary Newsom said. 

The couple said the process was frustrating, to say the least. 

Chris Newsom

"They didn't want to lose the case, so they didn't want to take the chance. For me, there was no chance. I wanted to do it," Mary Newsom said. 

Hugh Newsom recalled the promise to not give up that he made when he embraced his son's burned body in a bag at the funeral home. 

With that in mind, and in part at the urging of a lawyer friend from California who took an interest in the case, the Newsoms again went to prosecutors. 

This time, Deputy District Attorney General Leland Price agreed to reach out to the lawyer of another convicted killer in the case, George Thomas, in order to gauge interest in a deal for a sentence cut in exchange for testimony. 

RELATED: Convicted killer in Christian-Newsom case to testify in upcoming trial

In exchange for his testimony against Eric Boyd, Thomas' sentence would be reduced from life with the possibility of parole to 50 years behind bars, raising the possibility the convicted killer would be released in his sixties. 

Thomas agreed. 

"We got our man"

Thomas took the witness stand at Boyd's trial in early August. He described driving with Boyd to railroad tracks near Chipman Street and watching as Boyd marched Chris Newsom towards the tracks. 

He told the jury he saw three flashes as Boyd shot Newsom in the back and head and watched a "whoosh" of flames as Boyd set Newsom on fire. 

The jury convicted Boyd on all counts, a verdict the Newsoms wanted for years. 

"I felt like it has been so long to hear that," Mary Newsom said, choking back tears. "I waited so long to hear 'You're guilty.'" 

RELATED: After jury finds Eric Boyd guilty in their children's death, the Newsom and Christian families want their kids' lives remembered

But Thomas' testimony raised more questions than it answered about what happened that January night on Chipman Street. 

It was inconsistent with testimony from the seven previous trials in state and federal court. It did not allow time for the rape of Chris Newsom--a certainty indicated by his autopsy. 

"You never can seem to get the full facts from a person like that," Hugh Newsom said. 

"Maybe when we get to heaven, we'll find out what happened," Mary Newsom said. 

Still, the couple is pleased with Thomas' testimony--even if it was not the full truth. 

"I think that's what convicted Eric Boyd, and I have to be satisfied with that," Hugh Newsom said. 

Mary Newsom said a 12-year weight was lifted from the couple's shoulders the day of the verdict. 

Mary and Hugh Newsom
Mary and Hugh Newsom, photographed in their Halls home weeks after a jury found Eric Boyd guilty.
Cole Sullivan/WBIR

"Not having to get up every day and worry about 'Can we get him? Can we get him?' It has changed us," she said. 

The couple has planned a vacation for their upcoming wedding anniversary and has spent time with their son's friends in recent weeks. 

They said they are not concerned Thomas will be eligible for parole and out on the streets earlier than a judge initially ruled. 

"I always felt that his punishment was way too strict," Mary Newsom said.  

A new twist

But a hearing Wednesday cast doubt on whether the state would be able to uphold its end of the bargain with Thomas. 

RELATED: 'Promise is unenforceable': Judge says he cannot rule on Thomas's sentence deal until scope of agreement is determined

A judge asked Thomas' lawyer and prosecutors to present arguments to convince him he was able to carry out the deal. 

Boyd Trial day 2
Knox County Assistant District Attorney TaKisha Fitzgerald, right, questions George Thomas on the witness stand during the trial of Eric Boyd in Knox County Criminal Court on Wednesday, August 7, 2019.
Brianna Paciorka/News Sentinel

"I thought only the governor could commute a sentence," Judge Walter Kurtz said at the hearing. "Now you're telling me a prosecutor can commute a sentence."

Thomas did not show concern as he was led out of the courtroom, clutching a manila envelope of court documents in his handcuffed hands. 

The lawyers are due back in court Monday to work out details of the deal--and attempt to convince the judge to let Thomas out early. 

Boyd, the man the Newsoms worked for years to get behind bars, is now serving a life sentence. 

Not eligible for parole until he's in his late nineties, he will most likely die in a Tennessee state prison.