RAY BROOK, N.Y. (AP) — A New York state police major who led the manhunt for two killers who broke out of a prison says the surviving escapee is still cooperating with investigators a month after his capture.

Maj. Charles Guess said Wednesday every interview with David Sweat has been fruitful and he expects more as the investigation continues.

Sweat and Richard Matt broke out of Clinton Correctional Facility in northern New York on June 6. Matt was shot and killed by searchers June 26. Sweat was shot and captured two days later.

Sweat began giving investigators voluminous details of the escape shortly after his capture. Guess says police now know about 85 percent of the path the men took as they eluded an army of searchers for about three weeks.

A prison employee has pleaded guilty to helping them escape.