Police search dogs have picked up the scent of two convicted murderers who escaped from prison six days ago, a law enforcement source confirmed to CBS News Thursday.
According to the source, the dogs picked up the scent in New York's Cadyville community about three miles east of the maximum-security Clinton Correctional Facility in the northern part of the state, CBS News senior investigative producer Pat Milton reports.
Investigators also found candy wrappers and a foot imprint believed to be from either of the men, David Sweat, 34, or Richard Matt, 48.
A source told CBS News that the location was being treated like a crime scene. Bedding found in the area would be tested for DNA and examined for hair, and the wrappers would be checked for fingerprints.
It was unclear whether the men were at the Cadyville location days ago or more recently, Milton reports. However, it indicates that the men are on foot.
Investigators are hoping that the men are wet from the rain and are beginning to feel the effects of being outdoors, Milton reports. They may not have been equipped for outdoor survival because after escaping from prison they are believed to have planned on being picked up by a female prison employee.
According to the law enforcement source, Sweat has back problems and was on pain medicine at the prison.
Police blocked off the main road outside Cadyville as authorities on Thursday concentrated their sixth day of searching on a swampy area just a couple of miles from the prison.
State police closed Route 374 on Thursday morning as well as other nearby roads just east of Dannemora, where Sweat and Matt used power tools to cut their way out of the prison.
A police helicopter flew over a heavily wooded area dotted with swamps as troopers and corrections officers stood guard at regular intervals along a miles-long stretch of a nearby road. The search area appeared to be focused about 2 miles east of the prison, where the escape was discovered early Saturday by guards checking the inmates' neighboring cells.
Local schools were closed Thursday, and residents were told by authorities to lock their doors.
"I haven't really left my house in five days since all of this started," Saranac resident Thomas LaSalle told CBS News. "We had hundreds of armed correctional officers post themselves like every 100 feet up and down the road at about 9 p.m. last night and they remained there through the pouring rain, all night long until this morning."
The renewed activity so close to the prison appeared to be the best hope of catching the two convicts since Wednesday, when authorities acknowledged being in the dark about their whereabouts or doings, even as the hunt for the men expanded past state borders.
At a news conference outside the prison Wednesday, New York State Police Superintendent Joseph D'Amico said, "I have no information on where they are or what they're doing, to be honest with you."
Authorities expanded the search after investigators learned that the inmates had talked before last weekend's breakout about going to neighboring Vermont.
"We have information that suggests they thought New York was going to be hot. Vermont would be cooler, in terms of law enforcement," Vermont Gov. Peter Shumlin said at the news conference with New York Gov. Andrew Cuomo.
Shumlin and other officials would not say how authorities learned that information.
Meanwhile, another search began Wednesday night closer to the prison.
D'Amico said a prison employee - identified by sources to CBS News as Joyce Mitchell, a training supervisor at the prison tailor shop - had befriended the killers and "may have had some role in assisting them."
He would not elaborate.
On Wednesday, a law enforcement source confirmed to CBS News that the female prison employee allegedly was supposed to pick up the two inmates after they escaped, but she didn't show up. The source said she went to a hospital instead, apparently suffering from a panic attack, Milton reports.
When she got out of the hospital, the source said, she went to authorities and told them of her involvement in the escape plans.
She has been providing some good information to authorities, the source said. But she allegedly did not know the escapees' entire gameplan or what they intended to do if she didn't show up to drive them away.
The source said she is also believed to have allegedly assisted in some way with acquiring the power tools the pair used to escape.
Using the tools, Sweat and Matt cut through a steel wall, broke through bricks and crawled through a steam pipe before emerging through a manhole in the street outside the 3,000-inmate Clinton Correctional Facility in far northern New York, about 20 miles from the Canadian border.
The inmates may have had a head start of several hours before guards noticed they were missing, Cuomo said.
Unions representing guards and civilian staff members at the prison said many have been questioned by investigators, but no one has been disciplined or charged.
Vermont authorities are patrolling Lake Champlain and areas alongside it, Shumlin said. Cuomo urged the people of Vermont to be on the alert and report anything suspicious, warning: "Trust me, these men are nothing to be trifled with."
A road east of Dannemora remained closed Thursday morning at state troopers manned road blocks, and the 1,500-student Saranac Central School District called off classes because of all the police activity in the area 4 miles east of the prison.
As part of the search, state troopers and correction officers in helmets and body armor retraced their steps around the prison, checking garage doors, sheds, windows and other structures for signs of a break-in or other clues.
More than 450 federal and state law enforcement officers were taking part in the search, including customs agents, federal marshals and park rangers.
The killers' mugshots have been put on more than 50 digital billboards in New York, New Jersey, Massachusetts and Pennsylvania, police said, and a $100,000 reward has been posted.
Law enforcement officials again asked the public to report anything out of the ordinary.
"We don't want them out searching the woods," Sheriff David Favro said. "But if you're sitting on your porch, get your binoculars out and see if you see something unusual."
In Dannemora, Barbara McCasland said officers asked to search her home, but she told them no.
"I'm pretty battened down here," she said. "My windows are locked and everything."
As the manhunt dragged on, she said she was getting worried: "I wasn't in the beginning, but seeing that they've been out there so long, I am a little nervous."
Many in the prison town greeted the return of the searchers with a shrug. Many suspect Sweat and Matt are long gone and they are past any danger.
"I'm not worried about it," Jackie Trombley said.
Referring to the searchers swarming the area, she said: "We've got these guys down the road. They're everywhere, so it really doesn't bother me."