The evidence pointing to Cuba or Russia being behind Oswald has always been way more convincing. It was Oswald on his own or with backing from one of those two countries. Oswald had once tried to assassinate an army general, and had been in trouble as young man for shooting at people from a window.

In the year prior to his killing JFK Oswald had developed a close friendship with a Russian named George de Mohrenschildt, and he seemed to be Oswald's only close companion in the year leading up to the assassination.