The Difference Between The Office Of Sheriff And A Police Department
From early history, Sheriffs have been enforcing laws, protecting citizens and enforcing the will of King and Court. It is here the powers of the Sheriff originated in English Common Law, which has been absorbed into American Common Law and subsequently into the Constitution of the state of Tennessee.
The Office of Sheriff's primary obligation is to represent the sovereignty, authority, and interests of the State it's respective jurisdiction", whereas a Police Department represents the interests of the local jurisdiction.
Originally the Sheriff was the King's man, representing the interests and authority of the King in his Shire, often controlled by noblemen not always sympathetic or loyal to the King. In preserving the rights of the government, he (the Sheriff) represents the sovereignty of the state (Texas) and has no superior in his county.
The modern Office of Sheriff carries with it all of the common law powers, duties and responsibilities to preserve the peace, enforce the laws and arrest and commit to jail felons and other infractors of the law. The powers and duties of the Sheriff are analogous to those imposed upon police departments. The Sheriff is the principle conservator of the peace within the county.