Oct. 27, 2010 -- Ron Kempfert spent most of his life believing his father was a murderer. He said it was his mother who often fueled this horrible image of the man he called Dad.
"He's a murderer, he's a manipulator, he uses people, and that he didn't care about us, only cared about himself," Kempfert said his mother would tell him and his two brothers, Scott and Steve, when they were younger.
His father, Bill Macumber, who had no history of violence, was convicted in the 1970s in one of the most sensational murder cases in the history of Arizona. Macumber was sentenced to life in prison for killing Joyce Sterrenberg and Tim McKillop, both 20 years old, and leaving their bodies in the desert.
On May 24, 1962, the young couple was found shot and killed next to their car in an area now near Scottsdale, Ariz. The case went cold for 12 years until Macumber's wife, Carol Kempfert, went into the Maricopa County Sheriff's Office department where she worked and told her supervisors that her husband had confessed to the murders. Macumber was arrested a week later.
In 1975, Kempfert testified against her ex-husband, again saying that he confessed. The Arizona Republic reported that during the trial, two pieces of evidence allegedly had been collected by investigators at the scene and were also presented: a lifted palm print and bullet casings. At the time, prosecutors argued that the physical evidence linked Macumber to the murder scene.
Macumber was convicted of double homicide and sentenced to life in prison without the possibility of parole.
Ron Kempfert, now 42, had no doubt of his father's conviction, until he spoke with a prominent Phoenix defense attorney named Larry Hammond over the phone in 2003, 28 years after his father has been sent to jail. Hammond runs the Arizona Justice Project, an organization that works to free prisoners they decide could be innocent.
"He said 'I don't know how to tell you this, there is no way to tell you this -- we know your father, we think your father is innocent and we're pretty sure your mom framed him for it,'" Kempfert said of the phone call with Hammond.
After recovering from the initial shock, Kempfert started to untangle what his mother, Carol, had told him over the years and slowly the possibility that his father was innocent began to make sense.
"I love my mother but I don't like her. She is not a nice person and I did not make that jump immediately," he said. "I don't have any doubt anymore that my mom did it -- that my mom framed my dad for the murders."
Kempfert added that he eventually came to believe that his mother had a powerful motive. Around the time she turned her husband into police, Carol and Macumber's marriage was falling apart. At the time, Carol was working in the sheriff's office, where she had access to evidence from the cold case murder, and she had recently taken classes in lifting fingerprints.
Macumber on His Wife: 'I Hope She Burns in Hell'
Through Hammond, Kempfert has been reunited with his father, who has spent the last 35 years in prison.
"It's hard...how do you get across yourself that your mother is capable of this, that she framed your own father...for something he didn't do because she was going to lose what she had?" Kempfert said.
The Arizona Department of Corrections would not allow ABC News to interview Macumber in person, but he was allowed to give an interview over the phone.
"It's just blatant lies," Macumber said in his defense. "That's all it ever was from the beginning."
Macumber, now 75, said he has done his best to fight off bitterness, but what he is most angry about is his ex-wife's efforts to destroy his relationships with his three sons.
"Quite frankly the most unforgivable lie she ever told was to her own children, even after I was in prisons he told them their father was a murderer, he didn't love them or care for them, and hadn't made an effort to contact them and that was a terrible lie. I wrote dozens of letters to my children and every one of them came back refused. They never knew I wrote, they never knew I cared, and as a result of that I've lost two of my boys. I hope she burns in hell for that," he said.
Now living in Olympia, Washington, Carol Kempfert agreed to sit down for an exclusive interview with "Nightline" -- her first and only television interview. To this day, she denies she fabricated her husband's confession.
"Absolutely not...I didn't wake up one more morning and say, "Oh, gee, I think I'll go frame my husband today,'" she said. "I did not, and I will say this again, I did not manufacture nor did I ever tamper with evidence. Ever. And I passed four polygraphs and I'll be happy to take another. But I did not tamper with any evidence."
Kempfert told of how Macumber came home with his clothes covered in blood the night of the murders, and that he later confessed to her as their marriage was falling apart.
"It sounds (pause) ridiculous. But that's, in fact, what happened," she said.
Carol Kempfert Says Her Husband Is Manipulating Her Son
When asked how she felt about her son Ron turning his back and accusing her of framing his father, Kempfert blamed his actions on bad judgment.
"Critical thinking is not one of Ron's better skills," she said. "If anyone was ever made for Bill to mold and manipulate, it would be Ron."
Ron responded to his mother's accusations, "let's say I am gullible and my father is manipulating me but please tell me how he's manipulating the Arizona Justice Project?"
Adding fuel to his belief that his father is innocent, a man named Ernsesto Valenzuela allegedly confessed to three different people that he had committed the murders -- evidence the jury at Macumber's trial never was able to hear.
After Valenzuela died in prison in 1973, his former defense attorney, Tom O'Toole, came forward with his client's confession but the judge ruled it unreliable hearsay, reported The New York Times. O'Toole said attorney-client privilege kept him from presenting Valenzuela's confession until after his death.
"I believe [Valenzuela] told me about committing those murders because he got pleasure in committing those kinds of crimes and he relished it," O'Toole said. "He analogized shooting one of those people to it being like shooting a rabbit… he was thriving on it, he loved it."
Even after 35 years in prison, Macumber has been a model inmate. He's done charity work, counseled other inmates, was voted head of a local chapter of the civic group, the Jaycees, and even published a book of poetry.
He would have been eligible for parole 10 years ago if he'd agreed to confess his guilt, but he refused.
"Bill Macumber could never do that...he would rather die in prison than say he committed a crime he didn't commit," said his lawyer Larry Hammond.
Last year, Macumber and his attorneys petitioned the Arizona Board of Executive Clemency, which in a rare move unanimously recommended his sentence be commuted, saying "an injustice has been done in Mr. Macumber's case" and that his wife had "motive, means and opportunity to falsely pin the murders on Mr. Macumber."
But when the Clemency Board sent their recommendations to Arizona Governor Jan Brewer, the case came to a standstill. Brewer denied the recommendation for clemency in a one-sentence letter eight days after she announced she was running for reelection.
Ron Kempfert Confronts Governor Brewer About Denying His Father Clemency
"I was angry. We were making all the plans for him to come home. We thought it was a slam dunk...And you get a one sentence declaration: 'William Macumber's clemency is denied.' No explanation, it was devastating," Ron Kempfert said.
"It was hard to deal with," Macumber agreed.
Governor Brewer later explained that one of her reasons for denying Macumber's release was public safety concerns. But not only does Macumber have an exemplary prison record, he is in failing health with heart problems, arthritis and emphysema. His family fears he may not live long enough to get out of prison.
Weeks later, Kempfert went with ABC News to one of Brewer's press conferences, where he was given the chance to confront the governor about why she denied his father's freedom.
"It's an unfortunate situation that governors have to make difficult decisions regardless of what recommendations are made to them...but he was found guilty by two different juries and I feel very comfortable with my decision," Brewer said of her decision.
Afterwards, Kempfert said he wasn't surprised by the governor's reaction to his question.
"To me she's a coward, she just ran away, the moment it got tough. The same statement she's given us for a year," he said.
Macumber's legal team and his son continue to explore other options for securing his release, but options limited, and given Macumber's age and health, time is limited as well.