"There's no way I could ever have hurt my wife. I loved her. She's the mother of my children...I did not hurt my wife," he said in the 2008 interview.
Even his attorney, Guy James Gray, believed his client's story, donating his otherwise very expensive services and telling "20/20" in a 2008 interview that he "thought it was kind of a witch hunt."
Kari's family was told by the district attorney's office that even with the cell phone records and the other woman in Matt's life, it was not enough to prosecute the preacher.
"I think a lot of people thought that the case was sitting on a shelf somewhere," said Crawford Long, the McLennan County Assistant District Attorney. "We were actively doing things like the DNA, the fingerprinting, talking to the pathologist, doing everything we could."
Prosecutors finally broke a key witness, divorcee Vanessa Bulls. She had been interviewed several times, but never admitted to the affair or that she knew anything about Kari's death. Finally, a grand jury was gathered and Bulls was subpoenaed to testify.
When asked by Crawford Long if Matt Baker ever told her anything about Kari's death, he said, Bulls confessed to an affair with the preacher and knowledge of his alleged plans to kill his wife. "'Yes, he told me he killed her because of me,'" Long recalled her saying.
It was enough for prosecutors indict Matt Baker that same day.
The case went to trial in January of 2010, almost four years after Kari's death. Matt Baker did not testify, but Bulls told the jury jaw-dropping details about his plot to kill Kari.
CLICK HERE to see photos of Kari and Matt Baker through the years
After several days of testimony, it took the jury only eight hours to decide his fate: guilty. Baker was sentenced to 65 years in prison -- a verdict that seemed to stun the former preacher. After the verdict, Baker said in court, "I believe the jury made a mistake in this."
Though knowing Matt Baker is locked away has brought Kari's family some relief, they said the guilty verdict doesn't take away the sadness and pain that he has caused them.
"You took her from us, Matt," Dulin said in an emotionally charged victim impact statement. "You discarded her like she was yesterday's trash. You murdered the mother of your children and I still can't wrap my head or my heart around this... We forgive, because that's the only way, Matt. The only way that love makes the way, so that eventually, just in this case, love trumps evil."
The Bakers' two daughters, Kensi and Grace, currently live with their paternal grandparents in Kerrville, Texas. They travel to visits with the Dulin family each month. There is a custody case pending.