One of the things I have noticed over the years is that conspiracy theorists will often latch onto one detail that they think is odd, that doesn't quite jive with what you would expect from the official account, and use it as the basis of saying that the official account is a lie.
(Expect for a hyper-sentitivity to weirdness, that ignores the messy reality of reality..) So far, so good. There is nothing intrinsically wrong with finding a reason why the official story doesn't fit the observed facts. The problem occurs when they fail to ask themselves why that weirdness makes any more sense in their version of events.
Since what I just said there might not ring true, I'll give an example:
(The best example of this I have is "Why wouldn't they just actually shoot him from the book depository? It would be far simpler, shooters from different locations buys them little and seemingly serves to do nothing other than raise the suspicion of people like yourself.")
For various silly reasons, some "9/11 Truthers" think that empty remote controlled planes, probably controlled by the CIA or some other shadowy organization, were used in the 9/11 attacks. What they can never explain to me is why the CIA, or other shadowy organization, would use empty remote controlled planes instead of actually just hijacking planes.
Why all the stagecraft to imitate something that you could just actually do?
Remotely controlled planes are needlessly complex with too many opportunities for failure or discovery. Any weirdness surrounding the planes and their alleged passengers is far better explained by "reality is weird". Furthermore, that weirdness isn't resolved by "empty planes" since you are now supposing that the conspirators introduced those weirdnesses while inventing fake passengers. Why would they do that? Is that them tipping their hand to the conspiracy theorists?
It is simpler to just find a few lackies to actually do it.
None of these, I should note, seem terribly likely.
[WARNING GORE] https://www.youtube.com/watch?v=QTBInhsKW3E
Of course, that then leads to the conspiracy theorists claiming that the Zapruder film has been altered too. In fact, they believe that, incredibly, all available evidence was tampered with.
Why would the conspiracy plant a non-deformed bullet? Do they lack bullet deforming capabilities? Are they blithering idiots who, despite being idiots, have somehow managed to not get caught? Is the conspiracy of people who presumably just killed the president guilty of lazy or having poor planning?
A "non-deformed" bullet is better explained by weirdness inherent in the real world than some sort of conspiracy.
Here is how a competently run conspiracy would go down:
1) *Actually* shoot him from the book depository.
2) Enjoy success.
There is no reason to throw in an intermediate "plant a weirdly non-deformed bullet" step.http://i171.photobucket.com/albums/u320/ranb40/firearms/Notp...
Oswald used full metal jacket ammunition designed for piercing targets, and post-impact deformations for such bullets are often slight. (Incidentally, such ammo is not the best choice for an assassination, as hollow-point bullets that explode on impact are much deadlier. This is yet more evidence that Oswald wasn't a pro.)
Now back to George ... de Mohrenschildt ;)
http://youtu.be/DSBXW1-VGmM
It's clear from the timing and the geometry that a single bullet, originating from the Texas School Book Depository, did indeed hit both Kennedy and Connally.
Another cornerstone of the conspiracy case is that Kennedy's head moved "back and to the left" after being hit, when in fact the Zapruder film shows a sharp movement forward immediately after impact. This fact was uncovered by, of all people, Richard Feynman: http://assassinationscience.com/johncostella/jfk/intro/wound... (Warning: graphic imagery).
The real world is messy, and conspiracy theorists will always be able to find things to stoke their suspicions, even though many of the key "facts" underpinning the conspiracy theories have been debunked in the years since the assassination. It's clear at this point that no amount of evidence will convince some people that Kennedy was killed not by an elaborate plot but rather by a lone nutjob. But Oswald had the means (rifle & training), motive (desire, as a 24-year-old loser, to prove his importance to the world), and opportunity (a job in a building that happened to lie on the motorcade route published in the paper on 11/20 and 11/21). As Robert Oswald, Lee Harvey's brother, put it, the Kennedy assassination was one of those "happenstances of history"—undeniably, a bitter pill to swallow.