An eight year old boy shot his five-year-old sister dead when they were left home alone with a loaded gun, as the police arrested their mother’s lover on Monday, over the incident.The SunUK reported that, police said the little girl, Serenity Allen, was shot dead when her older brother fired a single round from a gun while they were inside their apartment, as their mother had left to go to a store when the shooting happened on Saturday.However, the police have ruled the killing as an accident but on Sunday, February 5, her 34-year-old boyfriend, Maurice Mobley, was arrested by the police after he turned himself in. He was charged with possession of a firearm by a convicted felon.See more photo of the little girl shoot dead below: