In the 42 years since the assassination of President Kennedy, here's what has been agreed on by those who still pursue one of the most sensational crimes in history: very little, if anything.

After the release of millions of pages of documents, and more than four decades of probes by professionals and amateurs, there is no consensus among those who toil in the conspiracy theory industry.

Some see the fingerprints of the Mafia, others the CIA. For some it was the Cubans, the Russians, Jimmy Hoffa or just about everyone who was anyone on or about Nov. 22, 1963.

No theory tying together disparate characters or events is too outlandish: Remember the Maine? Some even link the explosion that sank the U.S. battleship in Havana harbor in 1898 to the shooting of Kennedy 65 years later, the belief being that both marked trumped-up pretexts for American intervention in Cuba.

Interest comes to a head each year around the time of the assassination anniversary, which is Tuesday.

"To my knowledge, there have not been any new developments," said Nicola Longford, the executive director of The Sixth Floor Museum at Dealey Plaza in Dallas, where Kennedy was shot. "It's just part of the enduring myth and reality of this intoxicating story. It's just a continuing fascination with solving a mystery."

The Warren Commission concluded in 1964 that Lee Harvey Oswald was the lone gunman and squeezed off just three shots at Kennedy's motorcade from the Texas School Book Depository overlooking the plaza. A 1979 report by the House Select Committee on Assassinations concluded Oswald probably did not act alone — a contention supported by a majority of Americans polled in 2003, the 40th anniversary of the assassination.

A conference dedicated to "Cracking the JFK Case" recently drew roughly 100 people to a Bethesda, Md., hotel. Sessions covered everything from the CIA's monitoring of Oswald in the months prior to the assassination to what a Dallas police audio tape may — or may not — prove about the numbers of shots fired.

Former Sen. Gary Hart reminded participants that his own investigative foray into the case, as a member of the Church Committee that met in 1975 and 1976, revealed both the Mafia and the Cuban exile community had ample reasons to want Kennedy dead.

"It's an understatement to say there were some very, very unhappy people in both those camps," said Hart.

Jim Lesar, a Washington, D.C., attorney who helped organize the conference, said the three-day meeting was dedicated to the proposition that Kennedy's death remains an open investigation.

The move was in part a ploy to rekindle interest in JFK. Lesar cited last year's reopening of the investigation into the slaying of Emmett Till, a 14-year-old black boy murdered in 1955 after being accused of whistling at a white woman in Mississippi, as an example of what he'd like to see done with the Kennedy assassination.

"The Department of Justice is showing no inhibitions in dealing with 40-year-old civil rights cases, but the JFK case is being left to languish," Lesar said.

On the private side of the equation, he added that the lack of documents that could prove or disprove many theories hampers ongoing investigative efforts.

"There is still a load of information we need to accurately and completely understand what happened," Lesar said.

Meanwhile, the cadre of conspiracy theorists is growing older and grayer and sources are dying off, further slowing progress, conference participants said.

"The case seems frozen now, perhaps more than it's been for a number of years," said David Talbot, the founder of Salon.com, who is writing his own book on the case.