DURHAM, N.C. — An autopsy report on the death of a 4-year-old boy, who Durham authorities say was starved to death, shows he had previous injuries and died from malnutrition, dehydration and complications from pneumonia.

The boy's mother, Amber Dowen, 20, and her husband, Richard Dowen, 32, are both charged with murder in connection with the child's death.

In August, authorities say, Richard Dowen flagged down a Durham County sheriff's deputy along Interstate 40 to ask for directions to a hospital. When the deputy looked in the back of the tractor-trailer that Dowen was driving, he saw Amber Dowen holding her son, Randolph Thomas, who was wrapped in a towel.

The boy, who police said had bruises and marks on his chest, died the next day at Duke University Medical Center, weighing between 12 and 19 pounds. Investigators said they believe the abuse had lasted for several months.

Richard and Amber Dowen, both from Texas, are currently being held in the Durham County Jail without bond.