North Carolina ? A couple accused of tying their 13-year-old son to a tree for two nights to punish him for disobedience have been charged with murder in his death, authorities said Friday in Raleigh, N.C.

Brice Brian McMillan, 41, of Macclesfield, told a deputy that the child was being disobedient and was forced to sleep outside Tuesday while tied to a tree, the Edgecombe County Sheriff’s Office said. The teenager was released Wednesday morning but again tied up that night for bad behavior, authorities said.

The boy was left tied to the tree until the following afternoon when his stepmother found him unresponsive, Sheriff James Knight said. Knight said authorities believe the boy was bound to the tree with plastic ties and possibly other kinds of material.

“An adult couldn’t get out of those,” he said.

Temperatures in the area rose to above 90 degrees on Thursday afternoon, with a low of 73, according to the National Weather Service. Knight would not discuss any details on the cause of death, saying an autopsy was being conducted at the state chief medical examiner’s office in Chapel Hill.