The father of a missing Missouri mother of triplets said the woman's estranged husband "threatened her for a year" before she disappeared last month.

Stan Rawson, the father of 39-year-old Jacque Sue Waller, who was last seen June 1, said he has no doubt his son-in-law is responsible for her disappearance. Waller's husband, James "Clay" Waller, is the only "person of interest" who has been named in the case. 

Clay Waller is said to have told investigators that his wife walked away from his home in Jackson, Mo., on June 1 after the two quarreled following a divorce hearing that same day. He has denied involvement in his wife's disappearance, saying the police are conducting a "witch hunt" in investigating him.

Jacque Waller's family sees it differently.

"He’s not acting at all like someone whose wife came up missing," Rawson told Fox News in an interview Thursday.

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"They’ve got him," Rawson said of Waller. "All they need is her body."

Jacque Waller, who has 5-year-old triplets, drove to her estranged husband's home at around 4:00 p.m. June 1 to pick up her son, Maddox.

But the child was not at the home when Waller arrived, and family members say they think Clay Waller, a former police officer, lured her to the home to kill her.

"It’s a nightmare that never ends," the woman's mother, Ruby Rawson, told Fox News. 

Stan Rawson also said his daughter kept a "diary" on her company computer that detailed threats made by her husband. 

Police found the missing woman's car on June 2 abandoned along a Missouri highway. Her purse, keys and cell phone were missing from the vehicle. 

Jackson Police Chief James Humphreys told FoxNews.com on Tuesday that Clay Waller is "not cooperating the way we hope he would." He said authorities suspect foul play and believe it may have been a scene staged to look like an abduction.

Last week, a woman reported finding Jacque Waller's Blue Cross Blue Shield business cards along another state highway about eight miles from where her car was recovered. Waller worked as a manager for the health insurance company.

Her husband has said he had nothing to do with his wife's disappearance and accused police and the local community of launching a "witch hunt."

"It's crazy. I got a helicopter following me every day, police are following me," Waller told the Southeast Missourian. "I'll tell you what is not happening is that the cops are not searching for my wife."

"I have not done anything," he told the newspaper. "I miss my wife. I hope for a safe return."

Laura Helbig, a family friend and volunteer, told Fox News on Wednesday that Waller hasn't participated in the hunt for his wife, and said he's been seen mocking volunteers out on searches.

Helbig said Waller would "blow kisses, laugh, and flip us off" when driving by in his car during searches for Jacque. She claims such behavior was captured on video.

"I don't think this is the face or demeanor of a man who thinks his beloved wife needs to be found," Helbig said.

Anyone with information on Jacque Sue Waller is urged to call the Jackson Police Department at 573-243-3151.

SLIDESHOW: Where is Jacque Sue Waller? 

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