According to an arrest warrant, the child was found with trauma to her head and she lost consciousness. Officials said the girl had several bruises on her body, including a big one on her abdomen, forehead above her left eye, and on her forearm.
The child is in critical condition at Duke Medical Center. Authorities said the girl was hurt so badly that she was "currently unable to breathe on her own and remains in critical condition."
Sources said Royster was at the hospital visiting the young child when he was arrested.
Police charged Royster with inflicting serious bodily injury, assault with a deadly weapon and assault of a child under 12.
He is currently in jail under a $5 million bond.
Friends said Royster dated the child's mother for two months and the pair lived together. Royster's grandmother said she didn't know the woman and her child that well, but their living arrangement was not working out and she asked the couple to leave by Friday.