No magic bullet. Two (at least) shots, one in the neck/chest another in the right temple.
Think about the skill / luck of that shot. At some distance.
I don’t doubt that LHO did the shooting by himself. I’m just saying that’s some hellacious marksmanship on a moving target at distance.
I have seen the film many times but never that slowly. He is shot in the neck first and Jackie responds to him then he is hit on the head.