DALTON, Ga. -- A teacher is in custody after police say he barricaded himself inside a classroom at a high school in northwest Georgia Wednesday, police say. Police responded to the report of shot or shots fired at Dalton High School in Dalton and reported via Twitter that a person, believed to be a teacher, was barricaded inside. A Dalton police spokesperson told CBS News the teacher had a gun. CBS affiliate WDEF reports the situation began around 11:30 a.m. when the teacher blocked students from entering his class. When the principal tried to unlock the door, they heard a...