Who better than the Miami Herald's Glenn Garvin to tell us what the release of 30,000 secret documents about the John F. Kennedy assassination might reveal about 1960s Miami?

Here's his story:

If the federal government makes good on a 25-year-old pledge Thursday and releases 30,000 secret documents about the Kennedy assassination, the results might look a little bit like a 1963 Miami phone book.

The trove of files, mostly from the CIA and FBI, contains thousands of documents on South Florida people and organizations involved in efforts to topple Fidel Castro's communist Cuban government in the early 1960s, when that was practically Miami's leading industry.

Under a law enacted in 1992, the documents — supposedly the last batch of classified government files on the 1963 assassination of President John F. Kennedy — must be opened to the public no later than Thursday unless President Donald Trump intervenes to block the process.

Trump tweeted last weekend that he would go through with the declassification. But he left himself a bit of wiggle room by adding that his promise was "subject to the receipt of further information."

Subject to the receipt of further information, I will be allowing, as President, the long blocked and classified JFK FILES to be opened. — Donald J. Trump (@realDonaldTrump) October 21, 2017

That was a reference to fierce lobbying by the CIA and FBI to keep at least some of the documents secret — an effort that is still going on. "[CIA chief] Mike Pompeo is definitely fighting hard to hold them back," said Roger Stone, a longtime on-and-off Trump political associate.

Stone is also a Kennedy assassination researcher — his 2013 book “The Man Who Killed Kennedy” — argued that Vice President Lyndon Johnson was behind the killing — and he said he spoke to the president a week ago, urging that the release take place.

Stone is convinced that it will. But he noted that the last batch of assassination documents to be released was so heavily censored ("redacted," in CIA-speak) that much of it was useless. "I'm not confident we won't have that again, that there won't be a back-door bureaucratic effort to nullify the president's decision," he said.

Roger Stone, a longtime on-and-off Trump political associate, urged the release of the documents.

Roger Stone, a longtime on-and-off Trump political associate, urged the release of the documents.

Censorship isn't the only threat to the documents. The National Archive's last release of assassination files, in July, was marred by cyber-crash-and-burns that locked up computers for hours at a time. And researchers who got through found many of the documents were impenetrable pastiches of CIA jargon and code words.

"A lot of these files are going to be written in the language of the CIA's operational directorate, which is not easy for outsiders to comprehend," warned former CIA analyst Brian Latell, author of "Castro's Secrets: Cuban Intelligence, The CIA, and the Assassination of John F. Kennedy," which contends that the assassination was carried out with at least the knowledge — and perhaps even help — of the Castro regime.

Whether any of the South Florida-linked files are among those being hotly contested is impossible to know. But some assassination researchers told the Miami Herald that it's likely they are.

"The CIA is not trying to keep these things hidden because there's a signed confession to the Kennedy assassination in the archives," said Gerald Posner, the Miami Beach author of "Case Closed," which argues strongly that the assassination was not the result of a conspiracy. "It's doing it because there's stuff that's embarrassing. And one thing that might be embarrassing is some of the activities of these anti-Castro groups that the CIA was friendly with."

A peek inside the cyber-backdoor of the National Archives, where the documents are housed, reveals that many of those groups, their members and their associates are the subject of classified files. Using a digital search engine that the archives maintains to help it keep track of exactly what files it has, the Herald located nearly 3,000 files linked to various anti-Castro groups and figures — though their exact contents remains secret:

▪ Among the biggest caches of documents — over 1,600 pages of them — concerns militant Cuban exiles Luis Posada Carriles and Orlando Bosch, who lived in the Miami area off and on beginning in the 1960s. (Bosch died in 2011; Posada Carriles is believed to still be here.)

They partnered in various violent attacks on targets associated with the Castro regime — including, allegedly, the bombing of a Cubana airline flight that killed 77 people, though they denied it and were never convicted. Bosch specialized in bombings of Cuban diplomatic posts, Posada Carriles in attempts to assassinate Fidel Castro. His last known one, in Panama, took place in 2000. He was convicted, then pardoned.

▪ Convicted Watergate burglars Virgilio González, Bernard Barker, James McCord, Eugenio Martínez, and Frank Sturgis, along with their former CIA boss, Howard Hunt, are mentioned in a collective 764 pages of files. All the men participated in militant anti-Castro attacks, and all lived in Miami at various times from the 1960s onward. Hunt, Barker and Sturgis have all died. The others live in South Florida.

▪ More than a thousand pages of the classified files refer to Manuel Artime, who helped plan the CIA-backed 1961 Bay of Pigs invasion and then was captured ashore. Ransomed home by the U.S. government, he was on stage next to president Kennedy during a huge "welcome home" rally for captured participants in the invasion. Living in Miami, he spent the next several years on armed attacks on Cuba; he died in 1977.

▪ Ricardo Morales, better known by the nickname Monkey as he moved through the nightscape of Miami conspiracy and narcotrafficking in the early 1980s, is the subject of 172 pages of documents. A former Cuban intelligence officer who defected in 1960, Morales spent several years under contract with the CIA as a paramilitary officer, fighting secret wars in, among other places, Africa. Later he turned to freelance anti-Castro work — he, too, was accused but never convicted of involvement in the bombing of the Cubana airliner — and then drug-running. He was shot to death in a Key Biscayne bar brawl in 1982.

▪ Tony Cuesta, who blew off a hand and an eye during a 1966 raid on Cuba by his Miami-based militant group Commandos L but continued to mastermind attacks against the island until he died in 1992, is the subject of 48 pages. Two other Miami-based anti-Castro groups, Alpha 66 and the Revolutionary Student Directorate, figure in 112 pages.

Both Cuba and Miami-based anti-Castro exiles have long been near the center of the vast complex of theories about who killed Kennedy. The motive for the exiles, supposedly, is their rage at the lack of U.S. battlefield help during the Bay of Pigs invasion, particularly Kennedy's decision at the last minute to pull American air support.

Castro's purported motive is more direct: his knowledge that the Kennedy administration was trying to kill him through various exotic CIA-supplied weapons, including an exploding seashell and a poisoned diving suit. The Cuban dictator had even issued a not very veiled threat to an American reporter in Havana: "U.S. leaders should think if they are aiding terrorist plans to eliminate Cuban leaders they themselves will not be safe."

To add intrigue to the Cuba angle, Lee Harvey Oswald — the malcontent Texas Marxist who fired the bullets that killed Kennedy, according to the much-disputed official investigation conducted after the assassination by the Warren Commission — visited the Cuban and Russian embassies in Mexico City about six weeks before the assassination in search of visas to visit the two countries.

Journalist-historian Jefferson Morley believes that the documents scheduled for release this week may shed more light on what Oswald was up to and, more importantly in his view, what the CIA knew about him.

Morley's new book, "The Ghost: The Secret Life of CIA Spymaster James Jesus Angleton," offers evidence that Angleton — one of the most powerful yet cryptic spies in the history of American intelligence — knew Oswald was in Mexico and was following his activities closely.

Morley notes 151 pages of testimony Angleton gave in secret in 1975 to a U.S. Senate investigating CIA activities is among the documents scheduled for declassification. He think it may include material on Oswald's visit to Mexico.

"Angleton was interested in Oswald from the start and used him for intelligence purposes," Morley told the Herald. "From these files, we might find out a lot more about what those purposes were."