29-year-old Isaac Egbuka was charged Monday with second-degree murder, armed criminal action and domestic assault after the shooting early Monday in Cape Girardeau.
Police say Egbuka lived with his sister, who was babysitting the girl for a friend.
According to a probable cause statement, the woman told police Egbuka was intoxicated when they got into an argument while she was holding the baby.
The woman told officers she wasn’t aware her brother had a gun until she heard a gunshot and realized the baby was shot in the head. She said she believes her brother was trying to shoot her.
He is being held on $750,000 bond.