By Therese Apel JACKSON, Miss. (Reuters) - A man and woman in Mississippi were arrested and charged with murder on Sunday after two police officers were shot dead a day earlier while conducting a routine traffic stop in Hattiesburg, officials said. Marvin Banks, 29, and Joanie Calloway, 22, were each charged with two counts of capital murder, police said. Banks' brother Curtis, 26, was also arrested and charged with two counts of accessory after the fact of capital murder. Hattiesburg Mayor Johnny DuPree later told CNN that a fourth person had been arrested in connection with the case and booked on an obstruction of justice charge.