Tho I think Oswald was involved, I highly doubt he acted alone.
Some of his history that made him look guilty, also makes it unlikely that he acted alone. This starts with his joining of the Marines, defecting to Russia to join the communist party there, later he joined the communist movement for Cuba. To me, all this "joining" would make him more of a follower, not a leader or lone wolf.
If we compare him (Oswald) to Booth (the person who killed Lincoln), we see complete differences. Not only did Booth take on lead roles but bragged about shooting Lincoln prior to being killed. This contrasted how Oswald denied shooting JFK. Look, if your of the mind that shooting JFK was a righteous act that you committed alone, you would likely be proud of this action as Booth was and not deny it as Oswald did. On the other hand, if you were just following orders and felt that you were thrown under the bus, you might deny responsibility.
Another issue is the three shots. Tho they have done testing to show that the bolt action rifle could be fired three times within the time-frame, the last two shots were very close together, maybe too close for such a bolt action rifle. Not to mention that the third shot would be the most accurate with the least amount of aiming time. Tho it might be possible, I find it too unlikely.
Yet another thing I find a bit suspicious is the parade route. It's more than a bit suspicious how Oswald's moving to Dallas and his employment of the book depository so closely matched the the events of the parade and the final route. It is almost like someone was behind it manipulating the route and Oswald to be in the right place at the right time.
There is also the shooting of Oswald that shouts suspicion. Obviously, Oswald was the prime suspect and if he was found to be the lone gunman, he would be convicted and sentence to death anyway. That being the case, why would Ruby decide to kill Oswald himself when it would be done anyway. The simple reason would be that whoever was in charge didn't want Oswald to testify that others were involved or gave him orders.
Another theory has surfaced that someone in the Secret Service "accidentally" shot JFK from one of the following vehicles in the motorcade. Tho this theory has not been proven, it would explain some factors like how people in the motorcade smelled gunpowder and the closeness of the last two shots.
To me, tho I think Oswald was involved in the shooting, I think there is more than enough reason to believe he did not act alone.
It has been demonstrated over and over that an average qualified soldier could have made those shots. There is so much evidence pointing to him and it's been repeated and investigated ad nauseam. We have to do this silly dance with every single event in history. People need to get a life. All this black helicopter conspiracy garbage is really old.
The reasons Oswald was innocent were: the rifle Oswald used could not have possibly fired the rounds as quickly as the video showed, JFK's body moved backwards when he was hit instead of forwards like a person's body who was shot from behind would move and doctors who operated on JFK have stated that the bullet came through the front of his head, not the back. Oswald was only an average shot in the military, and the rifle he used (the carcano) is known for being inaccurate and having a lot of recoil, which would make it very difficult to hit Kennedy's head. Finally, Oswald was already unlinked and spied on by the government because he had lived in the USSR during the Cold War and probably suspected him of being a spy and probably wanted to get rid of him. I therefore believe Oswald was innocent