The report says Cheyenne Emery Yarley died from abusive head trauma. The infant was also sexually assaulted.
The girl's stepfather - 26-year-old Joshua Stepp - is charged with first-degree murder and first-degree sexual assault in her death.
He called 911from an apartment off Jones Franklin Road November 15 and told the operator the girl had swallowed toilet paper and wasn't breathing.
"I'm trying to, like, resuscitate her, and, uh, her heart is beating but she's not breathing," he said.
Paramedics tried to help the infant, but she was pronounced dead at WakeMed.
Stepp has been in jail without bond since his arrest.