OK. So we know Oswald did it. Why do so many people believe otherwise?
That, in my mind, is the only important question left when it comes to the JFK assassination.
Bryan Burrough, in his review of Bugliosi's Reclaiming History describes the appropriate response to the conspiracy theorists:
What Bugliosi has done is a public service; these people should be ridiculed, even shunned. It’s time we marginalized Kennedy conspiracy theorists the way we’ve marginalized smokers; next time one of your co-workers starts in about Oswald and the C.I.A., make him stand in the rain with the other outcasts.