For now, though, American journalists and historians tend still to ignore the widely available facts. Earlier this year, in an exchange with sports columnist Bill Simmons, Malcolm Gladwell endorsed baseball statistician Bill James' theory that the fatal shot was fired by one of Kennedy's own Secret Service men. "When you have lots of trigger-happy people and lots of guns and lots of excitement all situated in the same place at the same time," Gladwell wrote, unburdened by evidence, "sometimes stupid and tragic accidents happen."

We can likewise treat with skepticism the CIA's latest interpretation of Kennedy's murder, proposed by Brian Latell, a former Cuba specialist at the Agency. In a new book, Latell has updated and modified the unconvincing "Fidel Castro did it" theory that was that was first put forward by the CIA within hours of JFK's death and is still believed by some.

Latell now argues that Castro knew (via his DGI intelligence service) that Oswald posed a threat to JFK, but he did nothing. The heartless Cuban communist, he says, played a "passive but knowing" role in JFK's murder. As I reported in Salon last spring, the most basic corroboration for these claims is lacking, as even an otherwise approving reviewer had to acknowledge in the CIA's Studies in Intelligence publication.

Latell is on firmer ground when he suggests that the media's obsession with "conspiracy" obscures other more nuanced explanations of JFK's death. But his allegations advertently highlight a truth that the CIA and my friends in the Washington press corps prefer not to acknowledge: There is a lot more evidence of CIA negligence in JFK's assassination than Cuban complicity.

The record available online confirms that Oswald was well known to the CIA shortly before JFK was killed -- so well known, in fact, that a group of senior officials collaborated on a security review of him in October 1963. And these officials assured colleagues and the FBI that Oswald, far from being a dangerous Castroite, was actually "maturing" and thus becoming less of a threat.

Read this CIA cable (not declassified until 1993) from beginning to end. You will see that Oswald's travels, politics, intentions, and state of mind were known to six senior CIA officers as of October 10, 1963. At that date, JFK and Jackie were just beginning to think about their upcoming political trip to Dallas.

Because the CIA is so often caricatured in JFK discussions, some background is helpful in understanding who wrote this document and why.

In the fall of 1963, Oswald, a 23-year old ex-Marine, traveled from his hometown of New Orleans to Mexico City. There he contacted the Cuban and Soviet Embassies, seeking a visa to travel to both countries. A CIA wiretap picked up his telephone calls, which indicated he had been referred to a Soviet consular officer suspected of being a KGB assassination specialist. Win Scott, the respected chief of the CIA station in Mexico, was concerned. He sent a query to headquarters: Who is this guy Oswald?