Story highlights

U.S. Marshals add Richard Matt and David Sweat to "15 Most Wanted" fugitives list

Wanted posters of Matt and Sweat are being handed out at borders

Prosecutor: Prison employee told her husband about the escape after it happened

CNN —  

U.S. Marshals added the inmates who broke out of a maximum security prison in upstate New York to their 15 most wanted fugitives list and offered a $50,000 reward for information that leads to their capture.

The list “is reserved for the worst of the worst,” said U.S. Marshals Service Director Stacia Hylton. “There is no question David Sweat and Richard Matt fall into this category,” she said.

The massive manhunt for the convicted murderers, now in its 13th day, continued in the area of the Clinton Correctional Facility where state police have been checking seasonal camps and have cleared more than 160 abandoned buildings.

State police also asked hunters and homeowners with surveillance cameras to check their footage all the way back to June 6, the day of the prison break, for any unusual activity.

The search for Matt, 49, and Sweat, 35, has reached all the way to the borders Canada and Mexico, where wanted posters of the escaped killers are being handed out.

And as investigators widen their search for the fugitives, more details are emerging about the relationships between prison tailor shop instructor Joyce Mitchell and the escapees.

Before he broke out of prison, Matt at one point made a painting for Mitchell who is now accused of helping him and another inmate escape.

Using a photograph, Matt painted a picture of Mitchell’s children, Clinton County District Attorney Andrew Wylie told CNN.

And in April, Wylie said, Mitchell gave the painting to her husband as a wedding anniversary present. In exchange, Mitchell gave Matt a pair of speed bag gloves, similar to boxing gloves.

Authorities have also said Matt had a sexual relationship with Joyce Mitchell.

Mitchell, 51, is behind bars, accused of helping them break free and sneaking hacksaw blades, chisels, drill bits, a punch and other contraband into the convicts’ hands before they broke out.

Who are Richard Matt and David Sweat?

Cell phone records subpoenaed

Mitchell had been investigated in the past for an inappropriate relationship with Sweat that led corrections officials to move him out of the tailor shop in 2013 and keep them separated, Wylie said.

That’s the year when she started having a sexual relationship with Matt, a source close to the investigation told CNN. The sexual relationship took place at the tailor shop in the Clinton Correctional Facility, the only known place the two were together, the source said.

No court date has been set for Mitchell, who has pleaded not guilty to the two charges brought against her and has been talking to authorities. If convicted, Mitchell could face up to eight years behind bars.

The recordings of her conversations with investigators could total as much as 20 hours, her attorney said.

Investigators have also subpoenaed her cell phone records and found that she spoke with Matt’s daughter at least once, Wylie said.

Prosecutor: Husband didn’t know

Mitchell’s husband, Lyle, also worked in the prison’s tailoring block.

But the prosecutor said Wednesday that Lyle Mitchell didn’t know about the prisoners’ escape plan before it happened and wasn’t aware of his wife’s relationships with the inmates.

After Matt and Sweat broke out, Wylie said, Joyce Mitchell warned her husband that the men were free and had been plotting to kill him.

“She advised him after the escape of what happened, including the possible murder plot,” Wylie said.

Joyce Mitchell’s attorney says that doesn’t mean she was participating in the plot.

“I don’t believe she was involved in any attempt to kill her husband,” her attorney, Stephen Johnston, told CNN. “Just because she heard something doesn’t mean she was going to act on it. … She did not want to be a part of it and did not.”

Opinion: What will happen to the prison tailor?

Escape prompts closure of prison’s ‘honor block’

Investigators are looking into whether any other prison employees or inmates played a role in the escape.

The “honor block” at the prison, a special section that had housed Matt, Sweat and other inmates who’d gone years without significant disciplinary action, has been shut down after their escape and will now be turned into a regular cell block, a source with detailed knowledge of the Clinton Correctional facility told CNN.

Being in the honor block gave inmates privileges such as going outside every day, having hot plates and refrigerators in their cells, and congregating for hours in a central gallery area each evening with fellow inmates, said Rich Plumadore, who worked at the facility for 35 years.

Prison escape puts staff-inmate relationships in the spotlight

Wanted posters handed out at borders

The search area has expanded and shifted as hundreds of law enforcement officials scour the region of small towns and densely wooded countryside for clues.

“We are going to pursue every lead and we are going to locate these individuals,” said Capt. Robert LaFountain of the New York State Police Bureau of Criminal Investigation.

He and his colleagues have had plenty of leads to pursue. At the last count, police said they had developed more than 1,400.

And they have searched 16 square miles – more than 10,000 acres, which is the equivalent of almost 8,000 football fields.

DA: Convicts may have rehearsed their escape route at night

Time-progression photos of killers

So far, officials say, there’s no evidence Matt and Sweat have made it out of the search area in New York. But they can’t rule out the possibility.

Police issued "progression" photos of Richard Matt, left, and David Sweat, showing how they might look now.
New York State Police
Police issued "progression" photos of Richard Matt, left, and David Sweat, showing how they might look now.

“We have no signs of the two inmates being anywhere else but here,” Wylie said. “We haven’t had any burglaries, we haven’t had any stolen vehicles that we could tie into both Sweat and Matt.”

Authorities issued time-progression photos on Wednesday of the two fugitives that show what officials think the men would look like after more than 10 days on the run.

One theory is the two killers could be holed up in one of the hundreds of cabins scattered across the Adirondacks, the sprawling wilderness area at the doorstep of the prison.

Authorities are using canine teams and aircraft in the efforts to try to track them down.

Infamous manhunts: When police have tracked fugitives into the wild

CNN’s Randi Kaye, Alexandra Field, Jason Carroll, Julian Cummings, Jason Hanna, Polo Sandoval, Carolyn Sung and Shimon Prokupecz contributed to this report.