Updated

A 13-year-old left tied to a tree as punishment for 18 hours in June had been badly beaten and likely died from dehydration and heat stroke, an autopsy report showed.

The report, made public Monday, also says Tyler McMillan's body was covered with insect bites and he had bruises caused by a rod-like instrument and flesh missing from his buttocks. Marks on his wrists and ankles show he may have been restrained with plastic ties.

Authorities say Tyler McMillan's parents found him unresponsive on June 12 after he had been tied to a tree overnight as punishment. His father, Brice McMillan, and stepmother, Sandra McMillan, have been charged with murder and felony child abuse.

Autopsy results were released after Raleigh television station WRAL challenged a judge's order to seal the results based on a defense motion. Attorneys for WRAL wrote Superior Court Judge Franklin R. Brown in late October to challenge his ruling. The station received a copy of the autopsy on Monday, along with an order from Senior Resident Superior Court Judge Milton Fitch Jr. The station provided a copy to The Associated Press.

The report says Tyler McMillan's body temperature was 105.6 degrees when he arrived at the hospital. Brice McMillan told a deputy the teen was tied to a tree and forced to sleep outside on June 10 because he was being disobedient. Tyler McMillan was released the next morning, but again tied up that night for bad behavior.

The boy's stepmother found him the following afternoon, authorities said.

A dispatcher handling the 911 call on the incident repeatedly asked a woman and later a man what the 13-year-old was doing before he stopped breathing, but neither responded. The man said the boy did not have any medical problems. Toward the end of the call, neither responded to repeated questions from the dispatcher as they apparently performed CPR on the teen.

Two other children, ages 7 and 9, have been placed in the custody of the Department of Social Services.

Sandra and Brice McMillan are both scheduled to appear in an Edgecombe County courtroom on Jan. 13, 2009. Messages left with both of the McMillans' attorneys were not returned Monday afternoon.