Updated

North Carolina authorities are using a helicopter and bloodhounds to search for a convicted killer who walked away from a state prison farm.

James J. Ladd was first noticed missing Sunday morning, after the tractor he had been operating was found abandoned in a field outside the minimum security Tillery Correctional Center.

The 51-year-old was serving three life sentences for the 1980 robbery and shooting deaths of two men in Yadkin County.

Pamela Walker, a spokeswoman from the North Carolina Department of Public Safety, says it was not yet clear how long Ladd had been on the run before staff realized he was gone or local law enforcement was notified to be on the lookout. The first public notice of the escape was issued more than five hours after the abandoned tractor was found.