Mark Hacking (search) "just snapped" and killed his pregnant wife after she learned he had been lying for years about his education and career plans, his father declared Thursday.

"I think it's clear that this whole house of cards he had built, all this deception, had come to an end. He had been found out. His wife discovered his deception and confronted him with it, and I just think he just saw his whole world collapsing and broke down," the father, Douglas Hacking (search), told The Associated Press.

"He just snapped, and did something there's no explanation for. That's the only way I can envision it," he said.

Hacking said he based his belief in part on reports that Lori Hacking (search), 27, left work stunned and sobbing on July 16, three days before her husband, a 28-year-old hospital orderly, reported her missing. Colleagues at the brokerage firm where she worked told the AP they believe an administrator at a North Carolina medical school had called her back to say Mark Hacking wasn't enrolled there.

Early on, Douglas Hacking said he looked his son in the eyes and asked if he had anything to do with Lori's July 19 disappearance.

He said Mark denied it, then revealed to his brothers Scott and Lance on July 24 at a psychiatric ward that he had killed his wife in bed while she slept and threw her body in a trash bin.

Both Scott and his father are physicians, and Lance Hacking is an electronics engineer. Douglas Hacking said he believed Mark probably felt pressured by his family's achievements.

Hacking has said he was "completely blind-sided" by Mark's deceptions. Now the father says he's trying to reconstruct his son's life. He said he hasn't spoken lately to Mark, who was jailed Monday on suspicion of murder.

For years, Mark Hacking allegedly lied to his wife, family and friends about his education and career plans. Not only wasn't he enrolled at medical school, he hadn't applied. Nor had he graduated from the University of Utah. Yet he and his wife were packing for the move to Chapel Hill, N.C., and his deceptions were coming to an end, his father said.

On Thursday, a judge extended to Monday the deadline for District Attorney David Yocom (search) to file charges in the case.

Police believe Lori Hacking's remains will turn up in a municipal landfill, where they planned to return Thursday night with a team of cadaver dogs.

It could take a month for police and dogs to plow through 3,000 tons of compacted garbage buried 20-feet deep over an area of two football fields, and "luck is going to play in this whole thing," Detective Phil Eslinger said.