I was acting director of the F.B.I. on May 25, 1973, when Cox became the Watergate special prosecutor. It was my duty to respond to Cox’s request for help by providing F.B.I. agents to follow leads relating to the Watergate case.

My relationship with Cox was very professional. Every time he asked the F.B.I. for help in his investigation, I tried to be as responsive as possible.

Occasionally I would be called by the president, or more often by Al Haig, his chief of staff, complaining that Cox was investigating alleged wrongdoing that had nothing to do with Watergate. I would pass on their concerns to Cox.

In every case, the complaints from the White House resulted in Cox’s pulling back from areas of investigative concern outside his Watergate mandate. He was very sensitive to being accused of partisanship. Cox had been the solicitor general in the Kennedy administration. He could not have been more responsive to the White House’s complaints, even as he forged ahead with his investigation into Watergate.

After I left for Grand Rapids that October morning, the situation between the White House and Richardson began to rapidly deteriorate. Elliot called to let me know, and I returned to Washington on Wednesday evening. Three days later, Elliot and I resigned after refusing to carry out President Nixon’s order to fire the special prosecutor. Cox was then dismissed by Robert Bork, who had quickly been designated acting attorney general.

The resulting public firestorm, which became known as the “Saturday Night Massacre,” marked the beginning of the end of the Nixon presidency. Congressional support eroded, the House Judiciary Committee began impeachment hearings and the Supreme Court ordered the release of White House tapes capturing the president and his aides plotting the cover-up. Nearly 10 months after that October night, Nixon resigned.