Investigators raided the office of the Gwangju police chief Saturday as part of a widening probe into the police's suspected collusion with the father of the suspect in a high-profile murder case. The National Office of Investigation under the National Police Agency has formed a special team to investigate suspicions that the father, a police officer in the southwestern city of Gwangju, colluded with his colleagues to destroy evidence and access investigative information related to his son's all