OWLS HEAD, NY — (CNN) The man whose wife is accused of helping two killers escape a prison in upstate New York says the men planned to kill him.

Joyce Mitchell revealed the prisoners’ alleged plan to harm him shortly after their escape, Lyle Mitchell told NBC’s “Today” show in an exclusive interview that aired Tuesday. Escapee Richard Matt originally told Joyce he would give her pills that would knock her husband out, so she would have no problem leaving their home to come meet him.

“She told me that Matt wanted her to pick him up,” Lyle Mitchell said. But Joyce Mitchell refused to drug her husband, so the convicts got tough on her, she told him. “(Matt) started threatening her, (saying) someone inside the facility was going to do something to me, to harm me, or kill me, or somebody outside of the jail, if she didn’t stay with this,” Lyle Mitchell told NBC’s Matt Lauer.

But not staying with the plan is precisely what authorities say happened: Joyce Mitchell didn’t show up for the planned rendezvous with Matt and David Sweat on June 6. Instead, she checked herself into a hospital with panic attacks. “I was in over my head,” Lyle Mitchell said his wife told him. “She said she loved me but she was in too deep.”

Had she kept the date, she’d be dead now, Lyle Mitchell believes. And he might be, too.

He still loves his wife, though he’s mad at her, Mitchell said. But support her? “As of right now, I don’t know what to think,” he said.

Both of the Mitchells worked at the prison in its tailoring block, and investigators said Joyce Mitchell, 51, had a sexual relationship with Matt. Lyle Mitchell didn’t know about that relationship, Clinton County District Attorney Andrew Wylie said.

Meanwhile, authorities are combing an area west of the prison after DNA from Sweat and Matt was found inside a burglarized cabin, a law enforcement source told CNN.

The fugitives also left behind a number of personal items, including a pair of boots, in the hunting cabin in Mountain View, New York, a law enforcement source briefed on the investigation tells CNN. The boots, along with what appear to be provisions the pair may have planned to take with them, were discovered Saturday in the cabin located some 30 miles west of the Clinton Correctional Facility.

The discovery re-energized the search for the convicted killers, who haven’t been seen since their escape worthy of a movie script — at least not by authorities.

However, a witness on Saturday spotted someone running into the woods near a cabin in the Mountain View community, only 25 to 30 miles from the prison, according to acting Franklin County District Attorney Glenn MacNeill.

Investigators think the person spotted could have been one of the fugitive prisoners, MacNeill said.

Since then, law enforcement authorities have flooded the rugged terrain of Franklin County, swooping in on helicopters, cruisers and all-terrain vehicles to scour the region for the men.

Briefing reporters Monday, New York State Police Maj. Charles Guess declined to get into specifics about what was found at the cabin for fear of jeopardizing the search.

“It’s a confirmed lead for us,” he said. “It has generated a massive law enforcement response, as you can see, and we’re going to run this to ground.”

The break-in suggests the men “need provisions and are desperate,” a law enforcement source briefed on the investigation told CNN’s Deborah Feyerick. The huge manhunt for Matt, 48, and Sweat, 35, is now in its 18th day.

There’s no evidence the fugitives have the kind of support network they would need to get far away from the maximum security facility after their plan to get a ride from prison tailor Joyce Mitchell fell apart, the source said.

Searchers are having to contend with difficult conditions in the area, which is surrounded by dense forest and near a winter ski resort.

“Even in the area where we think they were last seen, it’s very rough terrain,” said Sheriff Kevin Mulverhill in Owls Head, Franklin County. “It’s not easy to get to, it’s not easy to traverse.”

Police are now working to contain the two men in the area, based on the understanding that they are running and on foot, the source said.

Officers at a series of road blocks in Franklin County were checking cars Monday, asking drivers to pop their trunks. Nearer to the cabin at the center of the search, the law enforcement presence grew heavier.

Authorities are concerned that Matt and Sweat may be monitoring radio communications, the source said, without being specific on whether the men have radios or similar devices giving them the ability to monitor police communications.

The sighting and DNA discovery explain the sudden influx of law enforcement teams into Franklin County. For much of the weekend, attention had been focused on an area near New York’s border with Pennsylvania, some 260 miles to the southwest of the prison, after somebody reported a possible sighting of the two fugitives.

That search wrapped up late Sunday, New York State Police said.

MacNeill urged residents of Franklin County to be alert for potential danger during the search for the escaped killers, whom authorities described last week as posing a “significant threat to anyone who may come into contact with them.”

“Be inside with the doors locked and very diligent,” MacNeill warned residents.

Some residents left the area, but others chose to stay put.

Shannon Hart said he visited cabins he takes care of on Monday not far from the one where the escapees are thought to have been.

He told CNN that he wasn’t concerned when he went out there because he was armed.

Matt and Sweat cut holes through steel cell walls, then shimmied along catwalks and through pipes before emerging from a manhole outside the prison gates and disappearing.

The tools they used may have been smuggled inside a frozen chunk of hamburger meat, a source familiar with the investigation told CNN on Monday.

Investigators are looking into whether Mitchell convinced a prison guard to pass the meat to the inmates in a way that bypassed a metal detector, the source said. The two escapees were housed in an honor block where they were allowed to cook their own food.

Their escape set off a massive search for them and an investigation of employees and practices at the prison.

Mitchell has been charged with aiding the escapees, and a corrections officer has been placed on paid leave, authorities have said.

Accused of helping the fugitives by supplying tools like chisels and drill bits, Mitchell is in jail and has pleaded not guilty to the charges against her.

The corrections officer placed on leave is Gene Palmer, a 28-year veteran of Clinton Correctional Facility who is cooperating fully with the investigation, his attorney Andrew Brockway told CNN.

Palmer knew Matt and Sweat for years at the prison and had received a painting done by Matt, Brockway said. But he wasn’t aware the inmates were planning an escape, the attorney stressed.

Palmer used Matt and Sweat as “sources” for information that he would “use to ensure the safety of his coworkers and of the facility, and of other inmates,” Brockway told CNN.

“He wants these two individuals to be caught, and anything that he can do to help law enforcement do their job, he’s willing to cooperate,” Brockway said Monday.

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