I have an embarrassing confession to make: when it comes to the “grassy knoll” and all that, I tend to agree with John Kerry and disagree with my esteemed colleague Adam Gopnik. Even today, fifty years on, some aspects of the official version of the Kennedy assassination don’t stack up for me.

Now, don’t get me wrong. I heartily concur with some of what Adam wrote in an erudite and enjoyable essay that appeared in the magazine a few weeks ago. And by that, I don’t just mean that we both have an affection for the final scene in “Double Indemnity,” in which the wounded murderer and tragi-hero, Walter (Fred McMurray), is confronted by his hardboiled boss, Keyes (Edward G. Robinson). Gopnik used the climactic scene as the leitmotif for his argument that the reason conspiracy theories survive is not because they contain any truth—he dismisses their promoters as “assassination obsessives”—but because the shooting itself still has enormous cultural resonance. In this telling, it marks a wrenching transition from a calmer age of trusted verities to our vortex of post-modern angst.

I’m not sure whether this theory, clever as it is, satisfies Karl Popper’s falsifiability criterion. I do readily concede that some of the doubters of the Warren Commission’s findings are (how to put it?) slightly off their rockers. In the copious annals of the assassination literature, you will find—and this is far from a complete list—suggestions that Kennedy’s body was desecrated to make it look as if the wounds had come from Lee Harvey Oswald’s rifle; that the real assassin was a mysterious man with a black umbrella who was standing on the parade route; and that the killing was the work of J. Edgar Hoover, Fidel Castro, the Mossad, or Lyndon B. Johnson. (Roger Stone, the rogue G.O.P. consultant, has a new book out fingering Kennedy’s successor as the evil mastermind.) Much of what passes for historical analysis is reheated gossip or speculation, and it’s driven more by the exigencies of the publishing industry, and other arms of the media-entertainment complex, than by a sincere desire to pin down the truth. (As you might have guessed, Stone’s book is selling well.)

But having said all that, there’s another, more substantive reason why the conspiracy theories survive: the official version of events begs questions; in some aspects, it beggars belief.

On the one hand, we are asked to accept that Oswald acted on his own and fired three bullets from his perch on the sixth floor of the Texas School Book Depository: one missed completely; another passed through the President’s neck and then hit his host, Texas Governor John Connally; and a third blasted off part of the President’s head. It’s not a wholly unreasonable story. Oswald was a withdrawn misanthrope, whose troubled childhood included being diagnosed as a schizoid personality. A leftist activist and one of life’s unhappy searchers, he fits the popular perception of lone nuts, and his training as a marksman in the U.S. Marine Corps suggests he had the wherewithal to shoot accurately. In the days before the assassination, he had been arguing with his wife, which may have pushed him over the edge.

At this stage, it should also be said, the “second gunman” theory, which was popular in the nineteen-seventies, has suffered some blows. Investigators for the Warren Commission interviewed numerous eyewitnesses who claimed to have heard shots fired from the grassy hill that was located in front and to the right of the motorcade, or from the railroad parking lot behind the knoll. (The Texas School Book Depository was behind the motorcade.) But no second gunman has been identified, and an audiotape that initially appeared to support the second-shooter theory was later discredited. It was this tape recording, which came from a Dictabelt worn by a Dallas cop, that helped persuade a congressional panel, the House Select Committee on Assassinations, to declare, in 1979, that “President John F. Kennedy was probably assassinated as the result of a conspiracy.” A subsequent investigation of the tape by the National Academy of Sciences concluded that the suspicious sounds weren’t necessarily additional gunshots. Some experts have even suggested that the bits of the tape containing the alleged shots may have been recorded a minute or two after the assassination.

“Case closed,” Fred Kaplan concludes in an informative post at Slate, wherein he describes himself as a reformed conspiracy buff. Perhaps Kaplan is right, but the ballistic evidence ruling out a second shooter is still disputed by some experts who have looked closely at it. One of them, Robert K. Tanenbaum, a former New York prosecutor who worked for the House Select Committee, insists that the location of Kennedy’s wounds was inconsistent with Oswald being the only shooter. “I believe without question there were shots that came from the side, the grassy knoll,” Tanenbaum, who served two terms as the mayor of Beverly Hills, recently told UPI.

Still, on this question, pending some further (and very belated) revelations, I’m willing to swallow my skepticism and accept the official story: Oswald was the lone shooter. But why did he do it, and was he maybe put up to it? It is here that the Secretary of State departs from the Warren Commission’s version of events. In an interview with NBC’s Tom Brokaw, Kerry said, “To this day, I have serious doubts that Lee Harvey Oswald acted alone.” And, he went on, “I’m not sure if anybody else was involved—I don’t go down that road with respect to the grassy-knoll theory and all that—but I have serious questions about whether they got to the bottom of Lee Harvey Oswald’s time and influence from Cuba and Russia…I think he was inspired somewhere, by something.”

Kerry isn’t the only one with unanswered questions about Oswald’s background. Almost certainly, we still don’t know all we might about his time in Russia, where he arrived as a defector in 1959; his interest in and support for the Cuban regime after his return to the United States; and his simultaneous links to people active in the anti-Castro movement, some of whom had connections to the mafia. “If you want to posit conspiracy, you must show associations,” G. Robert Blakey, a Notre Dame law professor who served as chief counsel to the House Select Committee on Assassinations, said in a 1993 interview with Frontline. “And in his simple surroundings, such as David Ferrie”—a boyhood friend whom Oswald may have taken up with again after his return to the United States—“are people in both organized crime and with anti-Castro Cubans.”

There is also the unresolved question of how the C.I.A. may have been connected to Oswald, or, at least, how closely it was tracking his movements. In [a letter to The New Yorker](http://www.newyorker.com/magazine/letters/2013/11/18/131118mama_mail) following the publication of Adam’s piece, Anthony Summers, a former BBC journalist who has written two books on the assassination, pointed out that more than seventeen hundred C.I.A. files pertaining to Oswald and the assassination remain classified. “If Oswald was a leftist loner who killed the President, and if that was all there was to it, why continue to conceal documents?” Summers asked.