Chuck Rhodes the attorney....

The district attorney (DA), in many jurisdictions in the United States, represents the government in the prosecution of criminal offenses. The district attorney – an elected or appointed official – is the highest officeholder in the legal department of the jurisdiction – generally the county in the U.S. – and supervises a staff of assistant or deputy district attorneys. Depending on the system in place, district attorneys may be appointed by the chief executive of the region or elected by the voters of the jurisdiction.

The title "district attorney" is used by several jurisdictions of the United States, including Massachusetts, New York, Nevada, Pennsylvania, Oklahoma, Oregon and Texas.
The United States Judiciary Act of 1789, Section 35, provided for the appointment of a person in each judicial district to prosecute federal crimes and to represent the United States in all civil actions to which it was a party. Initially, there were 13 districts to cover the 11 States that had by that time ratified the constitution. Each State was a district, except for Massachusetts and Virginia which formed two. Districts were added when additional States were admitted. The statute did not confer a title upon these local agents of federal authority, but subsequent statutes and court decisions referred to them most frequently as “district attorneys.” In 1948, the Judicial Code adopted the term “United States attorneys.”[1]

This term for a prosecutor originates with the traditional use of the term "district" for multi-county prosecutorial jurisdictions in several U.S. states. For example, New York appointed prosecutors to multi-county districts prior to 1813. Even after those states broke up such districts and started appointing or electing prosecutors for individual counties, they continued to use the title "district attorney" for the most senior prosecutor in a county rather than switch to "county attorney."

At the local level in other jurisdictions, officers such as the commonwealth's attorney, state's attorney, county attorney, circuit solicitor, or county prosecutor carry out functions similar to those performed by a district attorney.