NEW YORK — (CNN) When Richard Matt broke out of prison, he was looking forward to seeing his daughter. “I always promised you I would see you on the outside,” he wrote to her in a letter.

She received it in the mail three days after he and fellow inmate David Sweat escaped from the Clinton Correctional Facility in upstate New York, according to The Buffalo News.

Matt’s words were relayed to the paper, which cited unnamed law enforcement officials. The envelope was postmarked before the June 6 breakout.

The paper said there is no indication that Matt’s daughter knew ahead of time he was planning the break. CNN has reported that she cooperated with investigators while Matt was on the lam with Sweat.

“I’m a man of my word,” Matt wrote to his daughter.

But he was unable to keep it. Police shot him dead after he aimed a 20-gauge shotgun at an officer.

He and Sweat had split up. Matt had been hitting the bottle hard after they broke into a cabin.

And he was too out of shape to keep up, Sweat told officers when he was captured this week. That led to arguments.

When a U.S. Border Patrol special operations team found Matt a week ago, he was lying alone behind a fallen tree. He wouldn’t obey their commands.

Once they had shot him, officers could smell alcohol coming from his body from feet away.

Matt’s body arrived Friday at the John O. Roth Funeral Home in Tonawanda, New York, according to funeral home employee Marguerite Wilson.

Two days later, an officer shot and wounded Sweat less than 2 miles from the Canadian border.

From his hospital bed in Albany, New York, he has spilled baffling details about the prison break and the men’s time on the run.

Sweat and Matt pulled off the escape not once, but twice, he told investigators.

The first time was a dry run that took them through a labyrinth of pipes and tunnels, but they didn’t like the street they popped up in from a manhole. It had too many houses nearby.

While authorities initially spoke of the possible use of power tools in the escape, Sweat has said they found a sledgehammer in an underground passageway.

It was probably left behind inadvertently by a construction worker, according to a law enforcement official briefed on Sweat’s interviews with investigators.

The men supposedly used the sledgehammer to break down a brick wall on their way out of the maximum-security prison, the official said.

Sweat told investigators that he and Matt used only hacksaws to cut through their cell walls and a steam pipe inside the prison, Clinton County District Attorney Andrew Wylie told CNN.

During their time as fugitives, they had several close calls as authorities closed in, Wylie said.

While hiding in a hunting cabin, they heard voices nearby at one point.

And after the pair split up, Wylie said, Sweat saw a law enforcement officer walk right by him as he hid in a tree stand used by hunters.

Officials said the two had originally planned to come out of a manhole and meet prison tailor Joyce Mitchell, who would drive them away.

The Buffalo News reported that Matt encouraged Mitchell to establish a relationship with his daughter via text messages and phone calls.

The convicted murderers would then kill Mitchell’s husband, Lyle, before fleeing to Mexico, officials said.

Sweat has told investigators it was Mitchell’s idea for them to kill her husband, according to the law enforcement official briefed on his interviews. But her attorney denied that accusation Wednesday.

Joyce Mitchell told authorities that Matt and Sweat hatched the plan to kill her husband.

The night of the escape, Mitchell did not show up, forcing the fugitives to improvise on the run for more than three weeks.

Sweat will be turned over to the Corrections Department after his release from the hospital.

He is listed in fair condition and is expected to remain at Albany Medical Center for a few more days, according to the hospital.

Mitchell, the prison tailor, has admitted to smuggling hacksaw blades by hiding them in frozen hamburger meat and 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.

The escape has prompted prison officials to beef up security.

And the investigation extends beyond Mitchell and Palmer.

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, the New York State Department of Corrections and Community Supervision said.

The nine security staff employees include a watch commander who was covering for the usual midnight-duty lieutenant, a sergeant who was working mandatory overtime the night of the escape, and a female officer who had just transferred to Clinton, according to a Corrections Department source.

One possible avenue of investigation involves a melee with about 30 inmates that broke out at the prison one week before the escape, a Corrections Department source told CNN.

The department approved a partial lockdown that did not include the honor block, where Matt and Sweat were housed.

The May 29 brawl was reportedly brought under control in less than a minute and left one inmate with injuries that were not life-threatening, the source said.

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 told investigators that there was heroin use among prisoners and an alleged drug trade involving employees.

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