An autopsy determined the dead woman is black, the Indianapolis Star reported. But she had not yet been identified Tuesday afternoon.
Lauren Spierer, 20, a student at Indiana University in Bloomington was last seen June 3 when she left a friend's apartment.
Dorothy Mae Heard, 74, left her Noblesville house June in mid-June with nothing but her purse.
The unidentified body was discovered Sunday in Fall Creek, which joins the White River in Indianapolis. Investigators said it was in such bad condition that age, race and cause of death were not immediately apparent.