The Oklahoma Medical Examiner's office has ruled the death of an Owasso infant a homicide due to "multiple blunt impact injuries."
The boyfriend of the child's mother, Brandon Nordstedt, 22, is charged with child abuse murder and remains in the Tulsa County jail where he is being held without bond.
Emmy O'Rourke died in July at a Tulsa hospital.
Owasso Police said Nordstedt was alone with infant on June 11 and when paramedics arrived, she was unresponsive.
U.S. Marshals arrested Nordstedt in August in Hutchinson, Kansas returned him to Oklahoma.
Nordstedt has a preliminary hearing scheduled for October 22.