In many jurisdictions in the United States, a District Attorney (DA) is an elected or appointed government official who represents the government in the prosecution of criminal offenses. The district attorney is the highest officeholder in the jurisdiction's legal department and supervises a staff of assistant (ADA) or deputy district attorneys. Similar functions are carried out at the local level in other jurisdictions by officers named the Commonwealth's Attorney, State's Attorney, County Attorney, or County Prosecutor. Depending on the system in place in the particular state or county, district attorneys may be appointed by the chief executive of the region or elected by the people.
Because different levels of government in the U.S. operate independently of one another, there are many differences between people who perform this function at the federal, state, and county levels. The proper title for an appointed federal prosecutor at the local level (as opposed to an appointed U.S. Department of Justice prosecutor based in Washington, D.C.) is United States Attorney. Such officers are appointed by the President of the United States, serve under the Attorney General, and prosecute cases in the district courts of the federal government. United States Attorneys, in turn, hire prosecutors to handle the daily affairs of the office; they are known as Assistant United States Attorneys, or AUSAs.
Most US states also have an attorney who oversees prosecutions throughout the state, normally known as the Attorney General.
In the United Kingdom, positions equivalent to a District Attorney are the Chief Crown Prosecutors (or Crown Prosecutors in the case of Deputy or Assistant District Attorneys) of the Crown Prosecution Service in England and Wales, the Procurator Fiscal in Scotland, and the Director of Public Prosecutions in Northern Ireland. There is no direct American equivalent of the English Director of Public Prosecutions, who has legal responsibility for more than one million prosecutions annually in England and Wales. Many Commonwealth countries use Director of Public Prosecutions or Crown Prosecutor, while Canada uses the titles of Crown Attorney or Crown Counsel.
An Executive Assistant District Attorney (EADA), sometimes called the Chief Assistant District Attorney (CADA), or the First Assistant District Attorney is a title given to senior management in a prosecutor's office. The people who hold these titles are generally considered the second-in-command for the office, and usually report directly to the head prosecutor. The exact roles and job assignments for each title vary with each individual office, but generally include management of the daily activities and supervision of specialized divisions within the office.
In some offices the positions resembles that of the Executive Officer (XO) on a naval vessel, with the elected District Attorney as the Commanding Officer (CO). He or she reports directly to the District Attorney and acts as the district attorney in his or her absence. Often, the EADA may oversee or prosecute some of the larger crimes within the jurisdiction. In some offices the Executive Assistant District Attorney has the responsibility of hiring lawyers and other staff members in the District Attorney's office. Often, the EADA is in charge of giving press-releases and overseeing the work of the office staff. In jurisdictions where the elected prosecutor is the Commonwealth's Attorney a similar position is assigned the title of First Assistant Commonwealth's Attorney.