Halifax, N.C. — A man serving a life sentence for two 1980 murders escaped from a prison farm in Halifax County Sunday morning, according to the North Carolina Department of Public Safety.

Authorities estimate that James Ladd Jr., 51, escaped from the minimum-security Tillery Correctional Center around 10 a.m., said Keith Acree, a spokesman for the public safety department. A tractor Ladd had been running on the prison farm was found abandoned shortly before noon.

More than 50 people and dogs from the prison and local law enforcement agencies were searching for Ladd into the night. 

"Any inmate who has escaped from prison is a potential danger, because they're unpredictable," Acree said, adding that, as a prisoner, Ladd had a record of relatively minor, non-violent violations of rules.

Ladd robbed and killed two man on a Yadkin County farm on Nov. 26, 1980, authorities said. He was convicted of first- and second-degree murder and armed robbery in 1981 and sentenced to three consecutive life sentences.

Inmates at the minimum-security Tillery Correctional Center may work on the Caledonia and Odom prison farms, which are not fenced in. Acree said a security guard was supposed to periodically check on Ladd, who wasn't wearing a monitoring device, as he worked on the farm.

Anyone with information on Ladd's whereabouts is asked to call local law enforcement or the Tillery Correctional Center at 252-826-4165. He was wearing green pants and a white T-shirt when he escaped but has likely changed clothes since then, Acree said.