A convicted sex offender has been sentenced to 18 years in prison for killing a Warren County woman and leaving her burned body near a quarry in Summitville.The killer, Jimmy Byron Jones, 53, of Morrison entered guilty pleas this past week to charges of second-degree murder, abuse of a corpse, and tampering with evidence. He entered the pleas for the 2013 killing of Connie Brown, 58.His plea comes after he claimed to lawmen he acted in self-defense when Brown pulled a gun on him. He made the confession during questioning after he was charged.Jones was questioning after Brown’s body was found at an old quarry in Summitville.