A quick way to feed a conspiracy theory is to withhold or attempt to deflect information.

As conspiracies go, nothing can touch the John Kennedy assassination, one of the most studied and written about events in American history.

Last week’s release of some 2,891 never-before-seen secret files concerning those dark day in Dallas was supposed to help deflate the 54 years worth of conspiracy theories, spawning more than 2,000 books.

Instead, it fanned more flames.

First, due to national security concerns, more sensitive documents are being withheld and placed under a six-month review at the request of the FBI, CIA and other agencies.

Second, seeing some secret JFK files with blacked-out portions does not help the anti-conspiracy cause. Nothing raises more questions than seeing a document that has been heavily redacted.

The new cache of secret files includes one memo that even hints of a Tip-Off to the tragic events that unfolded in Texas. An anonymous call was made to a British newspaper 25 minutes before JFK was cut down in Dealey Plaza.

The memo to the FBI from former CIA Deputy Director James Angleton states: “The caller said only that the Cambridge News reporter should call the American Embassy in London for some big news and then hung up.”

Another file reveals that Lee Harvey Oswald met with a KGB sabotage and assassination officer less than two months before the assassination and that CIA agents speculated he might be a KGB agent.

Author Gerald Posner’s book “Case Closed” attempted to settle all the conspiracy questions by naming Oswald as the lone gunman in Dealey Plaza. Other books, like “The Reporter Who Knew Too Much” by Mark Shaw, have kept the conspiracy flames burning.

The book centers on Dorothy Kilgallen, the newspaper gossip columnist and TV game show panelist (“What’s My Line?”) who was investigating the assassination.

On Aug. 3, 1962, she dropped hints in her column about an affair between JFK and Marilyn Monroe. The next day, Monroe committed suicide.

Almost two years after the JFK assassination, Kilgallen was found dead of an alleged drug overdose in her Manhattan town house.

Circumstances of her death were similar to Monroe’s and came just weeks before a trip Kilgallen had planned to New Orleans to meet with a secret informant for a tell-all book she was planning on the assassination.

Kilgallen was the only reporter to have interviewed Jack Ruby, the Dallas bar owner who fatally shot Oswald at Dallas police headquarters.

The notes of her interview with Ruby and her papers on the case disappeared and have never been found.

She was also investigating crime boss Carlos Marcello, who she had suspected was the mastermind behind Kennedy’s assassination.

Charles Simpson, Kilgallen’s close friend, said she had told him: “If the wrong people knew what I know (about the JFK assassination), it would cost me my life.”

The fact that the FBI never got a confession to the shooting from Oswald haunted FBI boss J. Edgar Hoover, and those frustrations are evident in one of the recently released memos.

Without an Oswald confession, Hoover said he feared “the spread of conspiracy theories.”

On that point Hoover was correct. After more than half a century, conspiracy theories are buzzing more than ever.

By Jim Zbick | tneditor@tnonline.com