In the aftermath of the Watergate scandal, the Senate established its Select Committee to Study Governmental Operations with respect to Intelligence Activities, chaired by Senator Frank Church (D-ID)—informally known at the Church Committee.
It held hearings in 1975 and 1976, including taking sworn testimony from former FBI agents Courtney Evans and Cartha (“Deke”) DeLoach, who were the FBI liaison with, respectively, Presidents John Kennedy and Lyndon Johnson. Here is a brief overview of their testimony: Church Committee --FBI Analysis
And, here is the link to their full testimony: Church Committee --FBI Full Testimony
Book II, The Growth of Domestic Intelligence: 1936-1976, was published by the Government Printing Office on April 26,1976. It consists of some 122 pages, including over 800 footnotes. Here is the electronic link to that report: The Growth of Domestic Intelligence
It is important to remember that this report was authored by the Committee’s Democrat majority, who did their best to avoid any direct comparisons of the alleged dirty tricks and abuses of power that had figured so prominently in the unfolding of the Watergate scandal—particularly during the hearings of the Senate Select Committee on Presidential Campaign Activities and of the House Judiciary Committee’s Impeachment Inquiry. But, what is clear—from both the FBI testimony and the Committee’s Report—is that virtually every alleged abuse of the Nixon Administration had a counterpart in the prior administrations of Presidents Kennedy and Johnson.
Indeed, this is what led Renata Adler to author an essay on the first anniversary of Richard Nixon’s resignation—and in the midst of the Church Committee hearings—to suggest that their Committee had no grounds for recommending the impeachment of Richard Nixon and that their investigation—that did not seek to review any of the alleged abuses of prior administrations was more of a continuing cover-up that overshadowed that of the Watergate scandal. Her essay is entitled, Searching for the Real Richard Nixon Scandal, and appears as the first essay in her 2001 book, Canaries in the Mineshaft.