Iowa college student Mollie Tibbetts died from "multiple sharp force injuries," according to preliminary autopsy reports released Thursday by the state medical examiner.
The statement said her manner of death was homicide.
The 20-year-old's body was found Tuesday by state and local authorities after her accused killer, 24-year-old Cristhian Rivera, led investigators to her body, which was hidden in a cornfield, authorities said.
He has been charged with first-degree murder and is being held in lieu of $5 million cash-only bail.
The coroner's statement said further findings may be released.
Tibbetts was reported missing July 19, after she went on a run and never returned.