Everything we know about the elaborate maximum-security prison break in New York

Hundreds of law enforcement officials are now involved in search for the convicts.

Richard Matt, 48, was serving a sentence of 25 years to life for killing and dismembering his former boss in 1997. David Sweat, 34, was serving a life sentence for killing a sheriff's deputy.

Here's what we know so far about the two criminals and their escape from Clinton Correctional Facility:

• The men are thought to be highly dangerous. Detective Gabriel DiBernardo told The New York Times that "you can never have enough security with" Matt or "turn your back on him" because of his great efforts to elude police. Matt escaped from a jail in Erie County in 1986.
• Police are investigating whether the convicts had inside help in escaping. Authorities have questioned 51-year-old Joyce Mitchell, who works as an industrial training supervisor in the tailoring department, according to the New York Daily News. They're reportedly investigating whether she had a personal relationship with one of the two men.
• The escape was elaborate, as acting state corrections commissioner Anthony Annuci said Saturday at a news conference: "They went onto a catwalk which is about six stories high. We estimate they climbed down and had power tools and were able to get out to this facility through tunnels, cutting away at several spots." They then reportedly came out of a manhole outside prison walls.

• Matt and Sweat used hacksaws to cut through steel walls around air vents near their cots to create the hole they would escape through, according to the Daily News. They'd put the vents back in place as they were doing this work, which might taken place over a period of days or weeks, to avoid detection.
• To power the tools they used to cut through the steam pipes they crawled through to escape, Matt and Sweat used extension cords and hot-wired electrical junction boxes, according to the Daily News.
• To deter prison guards from figuring out they were gone, the duo reportedly stuffed their beds with clothes to make it look like they were there. Corrections officers are supposed to do bed checks every two hours, according to The New York Times. The inmates were reportedly discovered missing at a 5:30 a.m. bed check on Saturday.
• They left a note on one of the pipes. The yellow note had a smiley face and "have a nice day" written on it.

• Matt and Sweat were being held in an "honor block" of the prison, according to the Daily News. They were reportedly allowed to spend most of their time outside of their cells and working in a shop where they might have been able to gather the tools they used for their escape.
• The prison was undergoing construction work that contractors were brought in to carry out. Prisons have less control over contractors than they do over permanent staff members, Martin Horn, former commissioner of the New York City Department of Correction, told Business Insider. "Outside contractors may or may not comply with [the protocols]," he said. "A worker might be reluctant to report the tool as being lost over fear of losing their job."
• A source told the Daily News that prison guards would inspect the vehicles of contractors for contraband and prisoners hiding out, but would not keep a close watch over the tools the contractors had.

• Two witnesses reported seeing Matt and Sweat in their backyard after the pair escaped, according to ABC News. The backyard is near the manhole the men reportedly came out of. When the witnesses confronted the men, one of them reportedly said: "We're just lost. We don't know where we are. We're on the wrong street." They then both took off running, the witnesses said.
• The witnesses reportedly saw the men carrying a guitar case, which authorities believe the men used to carry the power tools that cut through the pipes.