Was Pastor's Double Life Motive for Murder?

July 8, 2010— -- Matt Baker was a Baptist preacher with an active congregation in Waco, Texas, and a beautiful family, including two young daughters.

But his seemingly picturesque life changed forever on April 7, 2006, when he found his wife, Kari, dead in their bed, apparently from an overdose of sleeping pills.

Love Story Starts During College Years

Kari and Matt met during their college years, and married after just three months of dating. They appeared to be the perfect couple from day one.

"It was a whirlwind romance," said Kari's mother, Linda Dulin.

Soon after, they began raising a family. Their life together looked so promising, until, without warning, Kari brought it to an abrupt end by snuffing out the storybook romance, authorities said, with a couple of wine coolers and a bottle of sleeping pills.

But why would a perfectly healthy mother leave a typed, unsigned suicide note professing love for her children, her parents and her husband, apologize and then take her own life?

In a 2008 interview, Matt Baker told ABC News that there were clues his wife was in a downward spiral. It began, he said, with one monumental tragedy -- the loss of their second daughter, Kassidy, who died over a decade ago. When she was a one year old, she was struck by a brain tumor and died four months after her diagnosis, leaving Kari grief-stricken. "She had a hole in her heart," Dulin recalled.

The Hewitt Police Department was quick to rule Kari's death a suicide. However, her family still could not comprehend how the doting mom could leave her other two children behind. Lindsey Pick, Kari's cousin, was sure that Kari did not take her own life.

"She would have never, ever left her children," she said.

CLICK HERE to see photos of Kari and Matt Baker through the years

Suicide or Murder?: A Family Investigates

Convinced suicide was not in Kari's nature, her mom, cousin, and aunts launched their own investigation. The first crucial clues in the case came when Linda Dulin received Kari's cell phone bill and noticed calls were still being made, even after Kari's death.

"Matt had given Kari's cell phone to someone and what that told me...was something wasn't right. Matt's story wasn't right," Dulin said.

That someone was Vanessa Bulls, a recently divorced single mom and church member, who was having an affair with Matt Baker while Kari was still alive.

Kari's family became increasingly suspicious of Baker and then their investigation uncovered even more stunning evidence: Kari's therapist revealed that Kari suspected Matt was having an affair and she feared he was out to get of her.

"Kari had shared with her [therapist] that she was afraid that Matt might possibly try to kill her and that she also found some crushed pills in Matt's briefcase," Kari's aunt, Kay Bailey told ABC News.

Preacher Maintains Innocence

Kari's family believed that Matt's double life was the motive behind what they believe was not a suicide, but Kari's murder. Matt maintained his innocence.

"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."

Key Witness: Divorcee Confesses to Affair With Preacher

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

'Murdering Minister' Found Guilty

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.