Joyce Mitchell may not have been escapees' only help
Police in far upstate New York are expanding their search beyond what was a 16-mile perimeter for two killers who've been on the run for 12 days.
A law enforcement source tells CBS News wanted posters of David Sweat and Richard Matt will be distributed at border crossings into Canada and in Mexico.
They escaped June 6 from the maximum security Clinton Correctional Facility in Dannemora, near the Canadian border.
And officials now believe multiple people were involved with helping the men escape.
Officers with assault weapons were still going door-to-door, searching homes, garages and sheds for any hint of the fugitives, reports CBS News correspondent Anna Werner.
More than 800 officers have been on the ground, in the air and on the water in an operation that is now believed to be costing about $1 million a day.
There was no sign of the escapees in Clinton County, but there was still a full court press in the present perimeter, the thinking being that the inmates may be just under searchers' noses, even though there have been no signs of Sweat and Matt, or carjackings or burglaries.
Investigators are now looking closely at how the men may have fled the area once they broke out of prison.
A law enforcement source told CBS News officials suspect they may have used prison employee Joyce Mitchell as "Plan B" and arranged for someone else to help them get away.
Law enforcement sources told CBS News the two men and prison employee Joyce Mitchell -- who is charged with helping them escape -- were involved in a plot to kill her husband, Lyle. Her lawyer has denied the charge.
"From what I can tell, she was not involved in a plan to do harm to her husband," said Mitchell's lawyer, Stephen Johnston.
He says the two are very close. Lyle visited Joyce in jail Tuesday, and is trying to raise money to bail her out.
"She is very upset, she's very weepy and very upset," Johnston said.
Peter Light, a correction officer at the facility for at least 30 years, said there are multiple problems with the way the facility is run that could lead to that kind of interaction. As an example, he said allowing inmates in the "honor block"' to wear civilian clothes is problematic, and something that was never done when he worked there.
"I have never seen that, never, never seen that before," he told Werner.
The risk with that, Light said, is it gives prisoners the ability to avoid "being recognized," and allows them to freely "get around."
Ron Hosko, a former assistant director of the FBI's criminal investigative division, told CBS News, "As the proactive leads start to get thinner and fewer, what law enforcement will do is self-generate leads. And this would be looking at other fugitive cases ... looking at how people were able to escape and elude capture for a very long time -- that is commonly changing your appearance and blending in."