Forty years ago, two unanswered questions loomed over the murky history of the FBI’s infamous pursuit of Rev. Martin Luther King Jr.: who were the top-secret informants who had fingered King’s confidante Stanley Levison as a former top Communist functionary, and who was the Atlanta informant who had burrowed into the headquarters of King’s Southern Christian Leadership Conference?

Across 1979 and 1980, I pursued those two mysteries. On the first, Emory University scholar Harvey Klehr provided a crucial assist; on the second, thousands of pages of imperfectly redacted documents sent to me pursuant to the Freedom of Information Act offered decisive clues. When I telephoned former FBI intelligence chief Charles “Chick” Brennan to cite brothers Jack and Morris Childs as the FBI’s top Communist sources, Brennan’s response confirmed Klehr’s clue: “How do you know those names?” Within 24 hours, FBI counterintelligence unit chief Michael Steinbeck called to say he was coming to visit me.

Steinbeck’s message was clear: should I proceed to publish the Childs brothers’ names, and that of former SCLC comptroller James A. Harrison as the FBI’s mole close to King, the Bureau would seek my indictment under the Espionage Act of 1917. I declined proffered meetings with President Jimmy Carter and then his successor, Ronald Reagan. In September 1981, my book “The FBI and Martin Luther King, Jr.”, was published, and The Washington Post named the Childs brothers on its front page while The Atlanta Journal did the same with Harrison. The FBI’s threat evaporated, but being told one should not publish accurate, historically important information may have had a formative effect upon me.

The FBI’s manifold files on King and his associates demonstrate two basic truths: when information and allegations came from human sources, as in the Childs’ fourth-hand claim that King had declared himself a Marxist, the FBI’s error rate could be high indeed. In contrast, when information came from telephone wiretaps and hotel room microphones where agents with tape recorders captured King’s every utterance, the FBI’s accuracy was extremely high.

In Atlanta, where the FBI wiretapped King’s home telephone from late 1963 until April 1965, and SCLC’s multiple phone lines from 1963 until June, 1966, agents stood by 24 hours a day in Peachtree Towers apartment 20-K to activate a reel-to-reel tape recorder whenever King himself came on the phone. Similarly, when agents trailed King to multiple cities across 1964 and 1965, bedside microphones transmitted everything that occurred in his hotel room to agents lurking in a neighboring room.

Some of what the agents recorded, and FBI headquarters transcribed, detailed how the abuse of women knew few bounds. Just as John F. Kennedy looked on while coercing a young White House intern to perform a sex act on a presidential buddy, FBI intelligence chief William Sullivan alleged that King looked on as a fellow pastor forcefully violated an unwilling woman. Since the tape recording of that episode, which FBI agents did nothing to stop, still exists under a time-limited court seal in a National Archives vault, come 2027 the accuracy of Sullivan’s allegation can be established.

One year ago, when the National Archives quietly put up on its web page over 54,000 links to U.S. intelligence community documents from the 1950s through the mid-1970s, I knew that the huge trove might well contain new material about important human FBI informants like James Harrison and famed Memphis photographer Ernest Withers. But the trove also contained dozens and dozens of new summary details and quotations from the Bureau’s recordings of King, the full transcripts of which remain sealed until 2027 pursuant to the court order.

Just as in 1980-81, when a scholar discovers the existence of historically significant new information, in this case documents which anyone with an internet connection can see and read, it would be historical malpractice to pretend that such documents are not in public view. No matter how unpalatable some of their content, for any serious scholar professionalism must trump politics.

The new documents indict J. Edgar Hoover’s FBI at least as much as they indict Dr. King. In addition to the FBI’s full complicity in the alleged forcible rape of a black woman, the new materials also implicate Hoover himself in the mailing of a notorious suicide letter and tape to King. For over 40 years the standard account had William Sullivan alone authorizing that vile act, but the new information credibly details how Hoover and his two top deputies were likewise complicit. Enriching and enlarging the historical record is a scholar’s uppermost responsibility, irrespective of whoever finds such new information unwelcome.

David J. Garrow’s books include “The FBI and Martin Luther King, Jr.” (1981), the Pulitzer Prize-winning King biography “Bearing the Cross” (1986), and “Rising Star: The Making of Barack Obama” (2017).