Richard W. Matt, one of the convicted murderers who staged an elaborate escape from New York's largest prison nearly three weeks ago, was killed on Friday in a burst of gunfire by federal agents, two people with knowledge of the situation said.
The shots rang out as law enforcement officers zeroed in on an area of remote terrain in Franklin County, near where investigators discovered evidence in two hunting cabins that indicated the missing inmates had been there. The fate of the other inmate, David Sweat, was unclear.
It marked a violent turn in a sprawling manhunt that began in Dannemora, N.Y., a village near the Canadian border, and soon spread to large swaths of the state after Mr. Sweat and Mr. Matt engineered a daring breakout from Clinton Correctional Facility.
The escape set off a statewide search on foot and by air, with hundreds of officers marching in tight formations through dense woods and checking on more than 2,000 tips.
The breakout, rare in its complexity and precision, relied on a combination of power tools and trickery, as well as alleged assistance from inside and outside the prison.
The men used dummies fashioned from sweatshirts to trick corrections officers into believing they were in bed and asleep. The men, who were in adjoining cells, each cut through the walls of their cells, then made their way into the bowels of the prison, cutting through steel, and emerged from a manhole into a neighborhood of vacant storefronts and clapboard houses just outside the prison.
Officials said the inmates made their escape late on Friday, June 5, or early Saturday, June 6. The corrections officers did not discover that the prisoners were missing until a bed check at 5:30 a.m. Saturday. The next day, Gov. Andrew M. Cuomo called the escape a "crisis situation for the state," and announced a $100,000 reward for information leading to their arrest.
The authorities have accused a civilian prison employee, Joyce E. Mitchell, of supplying the men with tools that aided in their escape, including hacksaw blades, chisels, a punch and a screwdriver bit.
A corrections officer, Gene Palmer, is accused of giving the men needle-nose pliers and a flathead screwdriver in exchange for paintings by Mr. Matt. Mr. Palmer, who was placed on administrative leave, was arrested and charged with promoting prison contraband, tampering with physical evidence and official misconduct.