Oswald murdered Kennedy with an entirely capable Italian military surplus rifle. It was a dead simple shooting feat for Oswald, combining his equipment and his USMC military marksmanship.
There's nothing else to the story.
The Leftists media and academia writing history who were alive at the time and/or alive today will NEVER reach a conclusion that a commie conspiracy was responsible for the death of President Kennedy.....NEVER, NEVER, NEVER.
The Left will go to great lengths to prove theories that the Mafia or other entities conspired to do the deed. It will not involve Moscow or Castro in the mix.
It just so happened that unstable, attention-seeking Oswald, by chance a communist sympathizer, decided to assassinate JFK and go down in history as a hero to some and a scoundrel to others....but he WOULD get royally noticed in either case. He was a lone-wolf psycho just like the guy that popped John Lennon.
The Mafia generally and historically won't get involved in conspiracies to take out presidents, popes or policemen by assassination no matter the provocation because they never want to call attention and the spotlight to themselves in this manner. They mostly stick to killing each other.