(CNN) -- David Sweat and Richard Matt didn't just pull off a grandiose prison escape, they actually did it twice.
And through it all, Sweat was the mastermind -- or at least that's what he's telling investigators, a local district attorney said.
From his hospital bed in Albany, Sweat is revealing more details about the New York prison break that seems to baffle almost everyone -- except himself.
An escape before the escape
Sweat said the plot to break out of Clinton Correctional Facility actually started in January, Clinton County District Attorney Andrew Wylie told CNN.
After five months of strategizing, Sweat and Matt made a practice run.
One night before prison tailor Joyce Mitchell was supposed to meet them at a manhole, Sweat and Matt escaped from their cells, a New York state official said.
They navigated through a maze of tunnels and pipes before popping out of a manhole. But Sweat said they saw too many houses near that manhole and decided to try for another manhole the next night, Wylie told NBC News.
"To make a dry run and ... have the ability to escape, and then go back in, it is a little baffling," he said.
So why didn't the guards notice? It's not clear, but the state Inspector General's office has been looking into whether guards had fallen asleep, officials told CNN.
After rampant speculation over what power tools the pair used, Sweat told investigators he and Matt used only hacksaws to carve through their cell walls and a steam pipe inside the prison, the district attorney told CNN.
Mitchell, the prison tailor, has admitted to smuggling hacksaw blades by hiding them in frozen hamburger meat and then having the meat delivered to Matt, a law enforcement official said last week.
She has been arrested and charged with promoting prison contraband and criminal facilitation.
Another employee, Gene Palmer, is accused of taking the meat to the inmates. He's charged with promoting dangerous prison contraband, two counts of destroying evidence and one count of official misconduct.
Dozen prison employees put on leave
But the probe extends far beyond Mitchell and Palmer -- and well beyond the escape.
Three members of the prison's executive team, along with nine security staff employees, have been placed on paid administrative leave as part of the review of the escape, said the New York State Department of Corrections and Community Supervision.
Superintendent Steven Racette and Deputy Superintendent Stephen Brown are among the executives on leave, a state official told CNN on Tuesday. The other is First Deputy Superintendent Donald Quinn, according to a source familiar with the investigation.
And the FBI is investigating possible broader corruption at the prison, law enforcement officials briefed on the case said. Agents are looking into whether drug trafficking or other criminal behavior among employees and inmates took place, officials said.
Some employees who have been questioned told investigators that there was heroin use among prisoners and an alleged drug trade involving employees.
How the plan derailed
According to Sweat, officials said, this is how the plan was supposed to play out:
Sweat and Matt would come out of a manhole and meet Mitchell, who would drive them away. The convicted murderers would then kill Mitchell's husband Lyle before fleeing to Mexico.
But Mitchell never showed up, forcing the fugitives to improvise on the run for more than three weeks. The two split up along the way, apparently because Sweat thought his older, less athletic partner was slowing him down, New York Gov. Andrew Cuomo said.
Police caught up with and killed Matt last Friday. Two days later, an officer shot and wounded Sweat less than 2 miles from the Canadian border.
Sweat's condition was listed as fair Tuesday night at Albany Medical Center.
Matt's family will not be claiming his body, so authorities in Franklin County, New York, will handle the burial, said Megan Avery at the Alice Hyde Medical Center in Malone. The body was at the medical center's morgue, and authorities could claim it as soon as Wednesday, Avery said.
Mitchell's husband 'still in love with her'
Never mind that Sweat, Matt and Mitchell allegedly planned to have Mitchell's husband killed before they drove off to Mexico. Mitchell's husband Lyle still loves his wife.
After all, Joyce Mitchell bailed on the plan to serve as the escapees' getaway driver, Lyle Mitchell's attorney told CNN.
"In a way, he's looking at it like Joyce saved his life that night by not picking them up," attorney Peter Dumas said.
"He's still in love with her, to put it bluntly. And I think he plans on waiting for her."
CNN's Ashley Fantz, Shimon Prokupecz, Danelle Garcia, Deborah Feyerick, Evan Perez, Don Lemon, Anderson Cooper, Carolyn Sung, Jean Casarez and Alexandra Field contributed to this report.
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