A prosecutor refers to a specific type of attorney who works for the state or federal government. They represent the people of the state or the nation during a criminal case. Some well-known prosecutors are people such as the District Attorney, Attorney General, and Solicitor General. A prosecutor's chief job is to ensure that justice is brought about in criminal cases heard in the United States.
Prosecutors are given some deference in deciding what cases to pursue. However, a prosecutor must pursue certain cases that a government body or officer require the prosecutor to pursue. In some instances, a prosecutor must first bring a case in front of a grand jury to decide if there is enough evidence to hold a jury trial. If the grand jury feels that there is enough evidence to bring a jury trial against a defendant, then the prosecutor must prove their case "beyond a reasonable doubt" to the jury in order for the defendant to be found guilty.