David Sweat shows up for a court date in August 2015. (Photo provided — Jason Cerone)

David Sweat, a cop killer who broke out of Dannemora’s maximum-security state prison with another murderer and spent three weeks on the run in 2015, has been transferred to the state prison in Attica.

Since his recapture, the 37-year-old had been held at Five Points Correctional Facility in Romulus, Seneca County. He lived in solitary confinement there in the prison’s Special Housing Unit and is also in the SHU at Attica, 100 miles west in Wyoming County, according to officials at the state department of Corrections and Community Supervision. He was moved Friday.

DOCCS officials offered few details about why Sweat was moved.

“Based on biannual reviews, which include looking at concerns like an inmate’s behavior, allegiances with other inmates that could become disruptive or over-familiarity with a facility, there are approximately 5,000 inmate transfers from one prison to another every month,” department spokesman Thomas Mailey said in a prepared statement. “Inmate David Sweat is one of the latest transfers.”

Even before the 2015 escape, Sweat was serving a life sentence for murdering a sheriff’s deputy in the Binghamton area.

Sweat has bragged that he was the mastermind behind his and Richard Matt’s escape from Clinton Correctional Facility in Dannemora. They had cells next to each other in the prison’s Honor Block and cut through the steel walls using contraband hacksaw blades. They had compromised a tailor shop supervisor and a guard to get the tools.

They explored the prison’s innards in the overnight hours, putting clothes-stuffed dummies in their beds to fool guards. Through the holes in the cells they accessed catwalks between the walls and, from there, tunnels beneath the prison. There they found tools left behind by contractors, and they broke through walls and cut into pipes to carve an escape route.

In early June they wriggled up to freedom through a manhole in a street outside the prison wall. The tailor shop supervisor failed to meet them, so they fled to the woods of the Adirondacks. They managed to keep running and hiding for three weeks while hundreds of police, prison guards, forest rangers and Border Patrol officers searched for them. Shortly after the two parted ways, a Border Patrol officer shot and killed Matt south of Malone. Two days later, a state trooper shot and captured Sweat in Constable, near the Canadian border.