Tell me profmunkin, do you really think it was totally impossible for someone to bring a rifle to work and shoot a victim riding slowly by in an open automobile at a range of less than 100 yards?
The victim was the most politically powerful, famous and instantly recognizable man on the planet. He was accompanied by the most famous and instantly recognizable woman on the planet: his wife.
The shooter, an ex-Marine marksman, owned and frequently practiced with the rifle later found at the site and conclusively linked to the murder.
The shooter, with a history of mental instability, political extremism and irresponsible acts including spousal abuse, had purchased the rifle under an alias earlier that year and used it almost immediately in a carefully planned attempt to murder another (not nearly as) politically famous person.
The shooter, given several days public notice of the victim's planned route, changed his routine significantly in obvious preparation.
The shooter had several hours alone in which to prepare a sniper's nest, assemble his rifle, and wait in what turned out to be an ideal location.
The victim was openly fond of public motorcades and had taken many in the past, often in built-up urban areas passing hundreds of buildings and thousands of windows, far too many to screen in advance.
Not only had those responsible for protecting the victim long been concerned about what became the exact scenario of the murder but the victim himself often recognized the risk, even that very morning. Despite repeated serious expressions of concern for his safety, the victim was philosophical, repeatedly instructing them to stay back and not impair the public's view. Since he was their boss, they could not overrule him.
Immediately after becoming a murderer, the shooter abandoned his weapon, left his place of work, went home, changed his clothes, picked up a revolver, and left again. A few minutes later, when he was stopped and questioned by a police officer, without provocation he emptied his revolver into the police officer and ran away, reloading, before perhaps a dozen witnesses.
He again attempted to shoot the policemen who finally apprehended him.
Yes, it's unsettling to think that a loser like Lee Harvey Oswald could bring down the most powerful and famous person in the world with such seeming ease. Yet, as I said, this was the exact scenario that the Secret Service had long feared, including the nature of the perpetrator as a loner extremely unlikely to conspire with or confide his plans in anyone who could inform on him. It may sound cold, but in retrospect the only really surprising thing about the JFK assassination is that it hadn't happened sooner. (A plot to kill JFK as President-elect using explosives had been thwarted almost by luck.) Fortunately, most people given the opportunity to see an American president in person don't try to kill him even if they strongly disagree with his politics.
As the saying goes, truth is often stranger than fiction. That's because fiction has to make sense; it has to seem plausible, while the truth only needs to be true. And the truth of the case against Oswald for double murder (and the attempted murder of Connally) has been established so far beyond any reasonable doubt as to be one of the few criminal cases in history that approaches proof beyond any doubt whatsoever.
