(AP) — A northeastern Nebraska man has pleaded not guilty in connection with the death of his girlfriend’s 14-month-old son.

21-year-old Mark Grant, of Winnebago, pleaded not guilty Wednesday in U.S. District Court in Omaha to one count of child abuse causing death. A trial date has not been set.

Court documents say Grant was caring for Julius Harlan on Sept. 10 when the boy received brain injuries. He died the next day at an Omaha hospital.

Investigators say Grant provided different stories about the circumstance behind the injury. He told authorities that he dropped the child on a bed and then shook him to revive him.

Court records do not indicate if Grant has an attorney.