WASHINGTON — There is a curious parallel between the current demands for release of the secret files of the Warren Commission and a House Committee which investigated the assassination of President John F. Kennedy, and a furor over long-sealed documents concerning the murder of Abraham Lincoln a century before.
And if this parallel continues, there will be severe disappointment for those who contend that these files provide the clinching evidence -- some magic piece of paper, some unheralded document -- that Kennedy was the victim of a wide-ranging conspiracy rather than of Lee Harvey Oswald, the lone gunman fingered by the Warren Commission.
But as in the Lincoln case, true believers in such a plot will not be put off by the lack of evidence. A determined and passionate breed, they will convince themselves, as they did in the Lincoln murder, that evidence of a conspiracy is lacking because the evidence has been destroyed to protect the conspirators.
Pressure for release of the files in the Kennedy case stems from the furor aroused by Oliver Stone's controversial movie, ''J.F.K.,'' Mr. Stone and other long-term conspiracy mongers charge that Kennedy was the victim of a conspiracy involving a wide range of suspects: the CIA, the FBI, successor Lyndon B. Johnson, the Mafia, billionaire Texas reactionaries, the military-industrial complex, Fidel Castro and anti-Castro Cuban exiles or all of the above.
Similarly, in the years following Lincoln's assassination on April 14, 1865, many Americans refused to accept the official version that the assassin, John Wilkes Booth, had, with the exception of a small band of henchmen, acted alone.
Instead, they were convinced Lincoln was the victim of a conspiracy. At one time or another, Booth is said to have been aided, abetted and controlled by forces as diverse as the Confederate government, the Catholic Church, the Masons and radical Republicans opposed to Lincoln's policy of conciliating the defeated South.
These charges came to a head in 1937, when Otto Eisenschiml, a wealthy Chicago chemist, published a book, ''Why Was Lincoln Murdered?'' that pinned the responsibility for the presidential assassination directly on Edwin M. Stanton, who served in Lincoln's cabinet as secretary of war.
By manipulating evidence and framing loaded questions as suggestions, Mr. Eisenschiml built a case that Stanton had conspired to murder his chief to make certain that the South was treated as a conquered province and the Republican Party would remain in control of the nation.
As in Mr. Stone's movie, there was just enough leavening of fact in Mr. Eisenschiml's sensational book to convince the uninitiated of the veracity of his charges. Only those with detailed knowledge of the affair could refute his ''evidence'' and disentangle fact from fiction.
Further fire was provided by another account, published two years later by Philip Van Doren Stern, ''The Man Who Killed Lincoln.''
Mr. Stern related that in 1923, a friend of Robert Todd Lincoln had visited the president's son and found him burning papers in a fireplace. These papers, Lincoln is supposed to have said, contained the evidence of treason by a member of his father's cabinet.
Having related this story, Mr. Stern added that the Lincoln papers, which had been deposited by Robert Lincoln in the Library of Congress, were to be opened in 1947. In that year, he said, ''we shall find out who it was that sat at the Cabinet table betraying the President and the people he served. Perhaps we shall even be able to trace some connection to the men who shared with John Wilkes Booth the responsibility for the murder of Abraham Lincoln.''
But when the papers were finally opened in 1947, nothing relating to the assassination was discovered.
That did not stop the conspiracy theorists, however. ''Whether Robert Todd Lincoln had destroyed important evidence or whether such evidence had never existed in this last great collection of Lincoln papers will probably never be known,'' Mr. Stern wrote in a later edition of his book.
The picture of Robert Lincoln burning ''evidence'' was promptly incorporated into a new grand conspiracy theory, and in a perverse way, seemed to confirm it. Undoubtedly, we can expect the repetition of this phenomenon when the documents in the Kennedy assassination are unsealed.
Nathan Miller is the author of ''Spying for America: The Hidden History of American Intelligence,'' and other books.