"The United States Attorney is the representative not of an
ordinary party to a controversy, but of a sovereignty whose
obligation to govern impartially is as compelling as its
obligation to govern at all; and whose interest, therefore, in a
criminal prosecution is not that it shall win a case, but that
justice be done. As such he is in a peculiar and very definite
sense the servant of the law, the twofold aim of which is that
guilt shall not escape or innocence suffer. He may prosecute
with earnestness and vigor -- indeed he should do so. But, while
he may strike hard blows, he is not at liberty to strike foul
ones. It is as much his duty to refrain from improper methods
calculated to produce a wrongful conviction as it is to use
every legitimate means to bring about a just one." -- Mr.
Justice Sutherland in Berger v. United States, 295 U.S. 88
(1935) The position of United States Attorney was created by the
Judiciary Act of 1789, which provided for the appointment in
each judicial district of a "[p]erson le