Though some people believe John W. Mathis murdered his wife and two of his children 30 years ago, he has support from a crucial source.

Mathis' surviving child, Duane, now 30 years old, proclaimed his father's innocence Friday in an interview with The Daily Republic.

"I don't believe he did it," Duane Mathis said in his first-ever interview about the murders. "If he did it, I wouldn't still be here."

Growing up with John Mathis as a father was tough at times, Duane acknowledged. He called his dad a "hard a**" and "true farmer" who worked long days and expected his son to do the same. But Duane said he never suffered anything worse than spankings from his father -- "no beat-downs, or anything like that."

Duane believes his own well-being proves his father could not have committed the murders.

"Why would he take them out, take their lives, but yet keep me?" Duane said. "What's different?

"If you live with a person for let's say 30-some years or whatever, and nothing happens to you -- there's no anger and he's not coming after you with deadly force -- I don't see how that could be, that he would be guilty."

LaDonna Mathis, 30, and her sons Brian, 4, and Patrick, 2, were shot dead in their beds during the early morning hours of Sept. 8, 1981, at the family farm near Mount Vernon. They were living in a farm shed at the time because a recent fire had destroyed the family home.

John Mathis, husband of LaDonna and father of the children, was arrested, tried and acquitted, and the case became one of the most-scrutinized crimes in state history. Some observers continue to believe, based on circumstantial evidence, the right man was charged with the murders.

Duane Mathis, then younger than a year old, was staying at his maternal grandparents' home when the murders happened. His parents probably thought a crowded shed was a bad sleeping environment for an infant, he said Friday.

Those same grandparents later said they believed John Mathis was guilty of murder, and they were estranged from Duane for some years following the trial.

Duane said it was his father who initially blocked the relationship.

"I think he was afraid if I went with them, they'd run away with me," Duane said. "That's what I would feel like. If somebody accuses you of something, and you give them your child, they might take off."

The couple, who resided in Mitchell, are now deceased.

Duane, who said he is expecting his first child with his girlfriend, resides on the acreage where his brothers and mother were murdered. The shed in which the crimes occurred still stands, but Duane said the presence of the building does not bother him.

"I wasn't there," he said. "So I don't think of it every time I walk out there."

John Mathis sold his farmland during the 1990s and has since moved off the acreage where the murders occurred, Duane said. John now works for a farmer in the area and, according to Duane, "still puts in 14-and-a-half, 15-hour days."

Duane went through school in Mount Vernon, where everyone knew him and his father and was familiar with the story of the murders. He does not recall anyone saying to him directly that they thought his father was guilty, though he's sure some people said it when he was out of earshot. Whatever sense of isolation he felt from being the son of a man tried for murder was mitigated by the presence of nearby relatives, including a paternal grandfather and some uncles, aunts and cousins.

Shortly after the murders, John Mathis built a home on his farm to replace that one that burned down. That's the house Duane grew up in, and the one he lives in today. He said pictures of his mother and brothers hung on the wall throughout his childhood, and his father, who has never remarried, always put flowers on their graves during Memorial Day weekends.

After high school, Duane joined the National Guard and served six years, including a year of wartime service in Iraq. "Nobody looks down on your name after that," he noted. He currently works as an audio/video technician.

The father and son have discussed the murders, but only rarely and briefly, Duane said. He believes his father has suffered silently.

"Us guys, we get angry at things, but we keep it hidden. But we're (upset) at the world," Duane said. "I get that, too, where I'm angry but I don't tell anybody what's wrong."

Duane's Friday call to The Daily Republic was sparked by a story the newspaper published on Thursday, exactly 30 years since the murders. The newspaper had made unsuccessful attempts to contact Duane and John Mathis for that story. Duane declined to have his picture taken Friday but came to the newspaper office following a phone interview and provided proof of his identity.

He said media reports came every year on the anniversary of the murders at first, but they have gradually waned and now appear only on the major anniversaries. Through it all, Duane said, he has been angry at what he considers one-sided coverage.

During the trial, John Mathis said he had been outside checking on some livestock when the murders happened in the middle of the night. He said he wrestled with the murderer -- a masked man -- upon his return to the shed, but the man got away. Mathis had a gunshot wound in his arm when investigators showed up, and he said it was from the confrontation with the murderer.

Friday, Duane said the masked man "never gets brought up," and he wants people to know there's another side to the story.

"You've got to get to know the person before you actually accuse them," he said. "Don't judge a book by its cover."