I will never buy Oswald was a lone shooter. He graded in the middle of sharpshooter, with a stationary target, and not using a bolt action rifle. I'll never accept he got off the 3 shots, with a bolt action on a moving target in 6 seconds.
No one ever showed where the bullets found on the 6th floor came from. There were 4 and 4 only. Those 6.5mm bullets were not very common but they NEVER traced where Oswald (or whoever) purchased them. I read once that there were only 2 gun stores in Dallas that carried them and Oswald didn't buy them there. They never found any type of bullet purchase made by Oswald of any mail order ammo. None.
Furthermore - they never found any evidence that Oswald had ever practiced shooting with that rifle (or anything else after he came back from Russia).
Oswald as the lone assassin makes no sense. If he was just a lone nut that wanted to get famous by shooting the President he passed up several BETTER opportunities.
1) When the limo made the left hand turn from Main onto Houston it slowed down to make the turn. That would have given Oswald a straight shot (or shots) at Kennedy at a time where the only direction the driver could go was TOWARDS the TSBD - right towards Oswald.
2) Assuming he didn't want that shot the limo made another severe left turn right UNDER Oswald - He could have dropped the rifle onto Kennedy from there and got his man.
Instead he allegedly waiting until the foliage from a Live Oak tree partially obscured the limo to start shooting. This makes no sense at all for a lone shooter. It does make sense if you have say another shooter in front of Kennedy say on the grassy knoll where all of the bystanders started running towards after the shooting stopped.
But hey - our government wouldn't lie to us would it?
[edit] if you want to see what a lone gunman Oswald would have passed up check out a disturbing game called JFK Reloaded. It puts you up on the 6th floor of the TSBD and simulates the motorcade. Very interesting if quite a bit tasteless.