Valid as it may be, even a notable new book will not quiet the conspiracy theories connected to the JFK assassination.

President John F. Kennedy was slain Nov. 22, 1963, in Dallas, and the evidence is overwhelming that one man, malcontent Lee Harvey Oswald, did the killing and acted alone.

But speculation, commercializing and theorizing about the tragedy has become a sort of cottage industry in the ensuing 44 years. Never off the table, the matter has been revitalized by the recent release of a book, “Reclaiming History,” by noted criminal prosecutor Vincent Bugliosi.

Bugliosi was the California lawyer who gained special fame by prosecuting murderer Charles Manson and co-authoring a book on the case, “Helter Skelter.” He says he has spent 20 years poring over virtually every theory and testimony ever offered about the Kennedy assassination. He consulted many solid sources.

“It’s my view that it’s impossible for any reasonable, rational person to read this book without being satisfied beyond all reasonable doubt that Oswald killed Kennedy and acted alone,” Bugliosi says.

A number of analysts who have read the well-promoted book suggest that the oft-parroted theories about the grassy knoll-Mafia-missing bullets conspiracy might at last be over, but that seems unlikely.

Time and again, reliable people, and Bugliosi is one of those, have established that Oswald acted alone but have succeeded only in rekindling uncertainty and doubt. Such reactions are inevitable in such a high-profile case, and chances are we have only begun to hear the rebuttals to the Bugliosi conclusions.

Bugliosi admits that such notions are invariably more interesting than the truth. Anyone conversant with rumors and how they proliferate can understand that. In the case of Kennedy, the prosecutor says, they point to a kind of collective inability to accept that such a monumental historical event could be caused by a single, ordinary person.

So the JFK murder again is on the conversation agenda. And no matter how good Bugliosi’s book may be, it will never sway the conspiracy devotees. We can be sure that the controversy will be as fresh as ever 100 years from now because there are those who consider their “truth” far more valid than that of the experts.