Lee Harvey Oswald
Oliver Stone. (And made it look like LBJ).
OJ
The real problem lay with the three way fist fight on the FIFTH floor of the Schoolbook depository between the Bilderburgers, the Comete de Saint Germain, and one of those Terminator thingies from the far future, who turned out to be not a robot at all, but one of the last members of the Fourth Reich from a secret Nazi base in the deep interior of the hollow earth at the North Pole.
It turns out that there was, in the late 16th century, a cabal of mutant vampires who stole the secret of hyperspacial flight from an alien race of small dog-people who have lived amunst us as supposed "pets" from the dawn of time, but the device has the effect of making every instant of recorded history happen all at once, which is the thing that makes time-travel possible. But the batteries were in backwards, reversing the effect, and creating a parallel timeline in which cyborg-JFK managed to win sixteen consecutive four year terms as President.
When that happened, well, the fertilizer hit the ventilator as far as the Red Lectoids were concerned; they shut down the whole human-flavored soft drink project in Area 51, and headed off planet, allowing the REAL power-brokers, athe Knights Templer and the Elders of Zion to reclaim the device, and convince a dufus named Oswald to take his lunch in a nearly empty corner on the sixth floor, making him the perfect patsy for the police body guard on the rear bumper of the limo, who shot JFK with a secret handgun built into a paperback copy of "Catcher in the Rye".
Not a chance in hell.