that's a lot of ifs...Oswald was a traitor. He should have been arrested when he came back to the US (with his Russian bride who was the daughter of a KGB officer) after renouncing his citizenship but he wasn't. It's damned likely that the CIA thought they could use Oswald so they recruited him and let him loose in society and the fools lost him. He turned up with a rifle in a Dallas building and killed JFK. Like any government investigation initiated by the government the primary mission of the Warren Commission was to cover the government's ass. The CIA was criminally negligent if Oswald was really an informant and the federal government was criminally negligent for allowing Oswald back into the Country.
We know Oswald pulled the trigger and we know Oswald killed a Police Officer trying to get away. The question is whether he acted alone and I say it doesn't make any difference. Why was Oswald allowed back into the US with his KGB bride with no restriction in the middle of the Cold War? He had to be a CIA agent or the government is criminally negligent but thanks to the Warren commission nobody as asking the important questions.