Just a few facts:
“Nobody who served with him in the USMC can remember his being an even mediocre marksman, much less the expert required ...”
This is a narrative oft repeated that is just absolutely silly. Claims that it was an “impossible” shot, he was a “lousy” shot, and the rest of it are absurd. Don’t you believe it.
Anybody who was graduated from the the United States Marine Corps boot camp in 1959 knows how to shoot. Maybe not “expert”, but they will be a competent rifleman. There is no debate about this.
The truth is, shooting a rifle and hitting a man size target, it just ain’t that hard even at 600 meters. People learn to do this in minutes. Oswald was shooting at 250 feet and had been practicing.
I agree that there are a lot of curious aspects about the assassination. However, the murder weapon belonged to Oswald, who worked at the warehouse, and he shot a policeman shortly afterwards. And no solid evidence has ever come out naming an accomplice or a co-conspirator.