Who killed JFK? new papers suggest dialogue between Ruby and Oswald

For many Americans, the assassination of John F Kennedy remains an unsolved crime, even though it is the most investigated murder in US history.

Yesterday, another layer was added to the rich mulch of conspiracy theories when Craig Watkins, the district attorney for Dallas County, announced the discovery of a transcript which allegedly details Lee Harvey Oswald's plot to kill Kennedy.

How 12 boxes of apparently authentic documents about the case remained out of sight for so long is a bigger mystery. The files were found in the courtroom safe of Mr Watkins' predecessor Henry Wade, and included personal letters, a gun holster and official records from the trial of Jack Ruby, who shot Oswald dead in the aftermath of the slaying.

Oswald apparently met Ruby on 4 October 1963 at Ruby's Dallas nightclub, the Carousel, two months before the assassination. They talked of wanting to get rid of JFK's brother, Attorney General Robert Kennedy. According to the transcript, Oswald said: "There is a way to get rid of him without killing him. I can shoot his brother. All I need is my rifle and a tall building."

Mr Watkins said the transcript would "open up the debate again about whether there was a conspiracy" to kill the President but Gary Mack, the curator of the Dallas Museum, poured water on the discovery.

"The fact that it is sitting in Henry Wade's file and he didn't do anything indicates he thought it wasn't worth anything," he said. "He probably kept it because it was funny. It's hilarious. It's like a bad B-movie."

The transcript echoes another looked at by the Warren Commission, which investigated the Kennedy killing and determined that Oswald was a lone gunman. The supposed conversation between Ruby and Oswald was deemed to be fake. Conspiracy theorists will nonetheless wallow in the details of the supposed joint plot between the two men.

Terri Moore, of the Dallas District Attorney's Office, believes the transcript is part of a film script that Mr Wade was working on.