A federal judge in Minnesota who has seen a sizable portion of the unreleased documents on the assassination of President John F. Kennedy says those documents, due to be released Thursday, won't be as exciting as many are hoping.

"The [Assassination Records Review Board] was very careful," Judge John Tunheim, who served on the board, told the Washington Examiner in an interview. "Anything that we saw that was information itself about the assassination or about any of the key players such as Lee Harvey Oswald was released, regardless of whether an agency wanted us to protect it or not."

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The ARRB was created by an act of Congress in 1992, largely in reaction to the conspiracy theories revived by Oliver Stone's movie "JFK," which was released in 1991.

With a staff of about 30 document reviewers, the five-person board systematically reviewed millions of pages of documents related to the JFK assassination from 1994 to 1998, and released most of them, an estimated 5 million pages.

The National Archives estimates 88 percent of the total documents were publicly available after the ARRB's work, and another 11 percent have been available since then, but were also partially redacted.

Most or all of the remaining one percent — three thousand pages that have never been seen at all, along with 34,000 that were redacted by the ARRB — will be made public this Thursday, which has historians, conspiracy theorists, and newshounds alike playing a guessing game of what might be so special as to remain unreleased.

But Tunheim gave a sober assessment of what the documents are likely to include, even though he hasn't seen them in over 20 years.

"What we protected was largely intelligence-gathering information," Tunheim told the Washington Examiner.

"So, it might have been the name of an intelligence agent which we protected until we thought that they probably would no longer be with us. Those names have already all been released in the intervening 20 years or so. But sources and methods of intelligence gathering, details of intelligence sharing relationships with foreign governments, foreign informants, a lot of that protected information had to do with the American government's intelligence and law enforcement relationships with foreign countries – that was a particularly sensitive area, and we agreed to more redactions on that basis. That is what the information is that will hopefully be released this week."

According to the 1992 law, any documents withheld by the ARRB would be protected for 25 years, which expires this Thursday. However, the act also said the president at the time could order the documents to continue to be withheld.

Over the weekend, President Trump tweeted that he would allow for the release of all the documents, but until the deed is done, there's always the chance that there could be a presidential change of mind.

Judge Tunheim is lending his voice to the sizable number who are saying that full transparency is the only remaining option.

"I believe that it's time to release everything if for no other reason than some assurance that we can give to people who are interested in the subject that the government is no longer hiding information that relates to the Kennedy assassination," Tunheim said.

"We would have liked to have released everything, but we had a statute that we had to apply, and, you know, there were legitimate reasons in the 1990's for continuing to protect some sources and methods of intelligence gathering," Tunheim added.

"We didn't protect very much, but what we did, I think it's long overdue to release."

Professor Patrick Maney, a historian at Boston College, agrees that it will be difficult for the president to make an argument to have the documents withheld any longer.

"My view is after this long of a time, it's hard for me to believe that any of these things would really jeopardize national security," Maney said.

As for the documents pertaining to other countries, Maney said most of those will relate to Cuba, the former Soviet Union, and also Mexico, because the CIA was keeping Oswald under surveillance during a 1963 trip to Mexico City in which he visited the Cuban embassy.

Maney believes in some cases, the CIA may have lobbied the ARRB to withhold documents that are more embarrassing than compromising.

"[The ARRB] indicated there is just a, whether you call it territorial, or there is a kind of bureaucratic imperative to withhold and conceal. And in a democracy, the imperative should be the opposite," he said. "It should be to disclose to the public."