Phelps County Sheriffs Department offers safety and security services to the residents of Phelps County. Based in Rolla, Mo., it operates two units, such as Criminal Investigations Unit and Criminal Interdiction Unit. The Criminal Investigations Unit undertakes inquiry of major crimes, which are time sensitive and requires much time for the process. It maintains contact with other agencies, such as Highway Patrol Division of Drug and Crime Control and Drug Enforcement Administration, to name a few. The Criminal Interdiction Unit is charged with identifying and stopping criminals involved in inner county and inner state crime related activities. The division also handles inner departmental personnel investigations, such as background exploration of prospective employees and internal examination.