After You Kill My Wife, Can You Feed My Dogs? Ariz. Man Allegedly Asked 'Hitman'

May 17, 2013— Phoenix, Ariz. -- After asking an undercover cop posing as a hitman to "whack" his ex-employee and kill his wife, Fred Knadler added a special request.

"If there is anything that I do love that's left, [it's] my two little puppies," Knadler said. "I would just like to make sure that -- it's a day or two before somebody finds someone -- that they have plenty of water and there's a bag of dog food in the laundry room."

When Patrick King, 45, took a job at Arizona Shower Door six years ago as a crane operator, all he wanted was to work hard and bring home a good paycheck to support his wife and kids. Never in a million years did he imagine he'd be sitting next to his boss and being asked to do the unthinkable.

And yet in January 2012, there King sat in his pickup truck, in the parking lot of a Phoenix bank, listening to his boss tell him that he needed to go dig a hole in the desert. His boss said that King would be given a bundle wrapped in a blanket to dispose of and that he would be paid $10,000 a year to keep quiet about it for the rest of his life.

If that sounds like an odd or even suspicious request, it wasn't, King said. In an interview with "20/20," he said he was expecting it -- which is why he brought a tape recorder and walked away with the evidence that would lead to the arrest of his boss, Fred Knadler, 75.

For years, Patrick said, he had done whatever Knadler asked of him. He worked 85- to 90-hour weeks, but claims he was paid only for a 40- hour week. King said he was also asked to fire several co-workers even though he was not part of the management team. And whenever King objected, he said, Knadler had a special way of reminding him who was boss.

"He made me carry a paycheck stub that said, 'Fred B. Knadler' on it," King said. "Two, three times a week, I'd have to pull out a paycheck. And he goes, 'Who signs your paycheck?' And I said, 'Well, it says Fred B. Knadler, sir.' He goes, 'Are we clear?' And I said, 'Crystal clear.'"

King said the longer he worked for Knadler, the more ruthless his boss became. At one point, Patrick said, Knadler even asked him to track his wife, Libby, using a cellphone GPS device.

"I complained about a lot of the stuff there and not wanting to do it, but I needed a job, and I had a family, so I did what I was told," King said.

That is, until that day in January 2012 in the parking lot, where Knadler had asked Patrick to meet him. The meeting came just months after Knadler had been served with divorce papers, and King said he had a hunch his boss was up to no good.

With a small tape recorder, King captured his boss' bizarre request to dispose of Knadler's dead wife's body in a hole in the desert. In exchange, Patrick would be paid handsomely to stay silent.

King went to police and handed over the tape. Fred Knadler was arrested that evening. His wife, Libby, 66, was found unharmed in her home.

Libby Knadler told "20/20" in an exclusive interview that, at first, she could not believe what the detectives were telling her about her husband's plans. Even now, she said, the reality of the situation has not hit her. She said her story was a cautionary tale to other women.

"Sometimes you don't realize ... when you are with a controlling person, what the outcome will be," she said.

Libby Knadler called King her "angel" and said she was forever grateful for what he did.

In a stunning turn of events, just a few months ago, before the start of Fred Knadler's trial, Libby Knadler and King received a call from the prosecutor handling the case. He informed them that Knadler had been caught on tape again. This time, as he sat in jail, he was attempting to hire an undercover police officer to kill Libby -- and Patrick, too.

Knadler now faces charges of conspiracy to commit murder and conspiracy to commit abandonment of a body. His trial is pending. He has pleaded not guilty.