Serenity Allen (photo via WJAX-TV) JACKSONVILLE, Fla. (AP) – A 5-year-old girl was fatally shot and her 4-year-old neighbor wounded in an accidental shooting in north Florida by the girl’s brother, authorities said Sunday. The children were alone in a Jacksonville apartment when the shooting occurred Saturday, Jacksonville Sheriff’s Office Chief Chris Butler said. Butler said the girl’s 8-year-old brother fired a single shot from a gun, fatally wounding his younger sister and wounding the 4-year-old boy with a non-life-threatening injury. Emergency personnel tried to save the girl but were unsuccessful. “We believe, in the absence of any other information being developed, that unfortunately this is a tragic, unfortunate accidental shooting,” Butler told The Florida Times-Union. He added that the mother of the girl had left to go to a store at the time. Police said 34-year-old Maurice Antonio Mobley, the mother’s boyfriend, was arrested after he turned himself in and charged with possession of a firearm by a convicted felon. Sheriff’s office spokesman Officer Christian Hancock said in a news release that police believe Mobley brought the gun into the house. It wasn’t immediately known if Mobley had an attorney. Butler said a therapist was called to help the boy who fired the shot. A sheriff’s statement added that the Florida Department of Children and Families and the state attorney’s office were also being consulted.