DANNEMORA, N.Y. » The two killers who cut their way out of a maximum-security prison apparently used tools routinely stored there by contractors, taking care to return them to their toolboxes after each night’s work so that no one would notice, a prosecutor said Sunday.

District Attorney Andrew Wylie also said that Joyce Mitchell, the prison tailoring shop instructor charged with helping the men escape, had agreed to pick them up in her car and drive off with them but backed out at the last minute because she still loved her husband and felt guilty for participating.

"Basically, when it was go-time and it was the actual day of the event, I do think she got cold feet and realized, ‘What am I doing?’" Wylie said. "Reality struck. She realized that, really, the grass wasn’t greener on the other side."

Wylie said there was no evidence the men had a "Plan B" once the getaway driver backed out, and no vehicles have been reported stolen in the area.

That has led searchers to believe the men are still near the Clinton Correctional Facility in Dannemora, where the manhunt was in its ninth day Sunday, with hundreds of law enforcement officers slogging through mosquito-infested woods, fields and swamps close to the Canadian border for Richard Matt and David Sweat.

At the same time, Gov. Andrew Cuomo cautioned that for all anyone knows, the convicts could be in Mexico by now.

Wylie said it apparently took a long time for the killers to complete their plan, working methodically between midnight and 5 a.m. over many nights.

"They had access, from what we understand, to other tools left in the facility by contractors under policy and were able to open the toolboxes and use those tools and then put them back so nobody would notice," the prosecutor said.

He also said the men had been scouting out the tunnel system under the prison at night for the best way get out.

The convicts used power tools to cut through the back of their adjacent cells, broke through a brick wall, then cut into a steam pipe and slithered through it, finally emerging outside the prison walls through a manhole, authorities said.

Workers on Sunday welded shut a manhole at the base of a wall on the side of the prison where the two men escaped. They also sealed two other manholes on the street near prison, including the one the convicts climbed out of.

Mitchell, 51, was charged Friday with supplying hacksaw blades, chisels, a punch and a screwdriver. Her lawyer entered a not guilty plea on her behalf, and her son Tobey told NBC she would not have helped the inmates break out.

Wylie said Sunday the two inmates planned to have Mitchell drive them about seven hours away to an unknown destination.

Residents were very much on edge, with some saying they were keeping guns handy. But there was also an outpouring of support for the search effort. A restaurant urged people to tie blue ribbons around trees and mailboxes.

"The locals have been awesome," said Sgt. Barry Cartier of the Franklin County Sheriff’s Department, part of a crew from a neighboring county working 12-hour shifts. "They come around with food all the time. We’ve got too much to eat."

Sweat, 35, was serving a life sentence without parole for killing a sheriff’s deputy. Matt, 48, was doing 25 years to life for the 1997 kidnap, torture and hacksaw dismemberment of his former boss.

Associated Press video journalist Joseph B. Frederick in Cadyville, New York, contributed to this report.