After President Nixon’s Attorney General John Mitchel was forced to resign because of his involvement in the coverup of the Watergate break-in, Nixon appointed Elliot Richardson to be Attorney General. Richardson, in turn, appointed Harvard Law School Professor Archibald Cox as Special Prosecutor to investigate the Watergate affair. During the Senate Watergate hearing during the summer of 1973, it became known that the White House had taped all conversations in the Oval Office. Cox subpoenaed the tapes, Nixon refused to disclose them, claiming executive privilege. The Courts overruled this claim, and Cox continued to demand the release of the recordings. Nixon demanded that he stop. When he refused, on Saturday, October 20th, Nixon ordered the firing of Cox. Elliot Richardson and his assistant, William Ruckelshaus, refused to carry out the order and resigned, so it was left to Solicitor General Robert Bork to fire him. This became known as the Saturday Night Massacre.