sentences:  In most states, the county sheriff is the chief law enforcement officer in the county.However, except in major emergencies where clear chains of command are essential, the county sheriff normally does not directly control the police departments of city governments, but merely cooperates with them (e.g., under mutual aid pacts).Thus, the most common interaction between county and city law enforcement personnel is when city police officers deliver suspects to sheriff's deputies for detention or incarceration in the county jail.