The Ottawa County Sheriff's Office has asked the Oklahoma State Bureau of Investigation to assist its office in looking into the death of a 5-year-old.
Medics arrived at a home in Miami, Okla., on Wednesday to find Conner Jackson Kreider-Reece dead.
The OSBI says, as a 2-month-old, Conner suffered a severe brain injury at the hands of his father, 27-year-old Henry Moland.
At that time, Bartlesville Police said Moland struck Conner's head on a coffee table and shook him several times.
Moland was sentenced to 30 years in prison for child abuse by injury after he pleaded guilty before a Washington County judge.
Authorities have not said whether Conner's death was related to his earlier injury.