Both the CIA and the FBI witheld important information from the Warren Commission. The CIA didn't tell them about "Operation Mongoose," the plan to use the Mafia to help get rid of Castro, nor did they tell them about their surveillance of the Cuban and Soviet embassies in Mexico City--where they had double agents and had observed Oswald's visits in September 1963. The FBI didn't tell the Commission about unauthorized wiretaps they had, on which Marcello, Trafficante and others talked about wanting JFK and/or RFK dead.

Within days of the assassination, J. Edgar Hoover told LBJ that Oswald had acted alone. The Bureau produced a five-volume, 25,000-page "report," using 2,500 interviews--and presented it to the Warren Commission just four days after the Commission's first meeting, in early December 1963. Plus, the Commission was in a big hurry to conclude its work before the 1964 Presidential election.

None of the above necessarily proves that JFK was the victim of a conspiracy. But, given the large volume of information that both agencies witheld, and the indecent haste with which the Commission concluded its work--and the passage of almost half a century--we can't conclude with certainty that there wasn't a conspiracy to kill JFK. All that's certain is that we'll never know for sure.