In the early frames of Zapruder, we miss him lifting a gun toward his head. He accidentally fires the gun and shoots Connelly, as he drops it.
When the car clears the highway sign, his hands are still up in front of his his throat reacting to dropping the gun. When the gun hits the red phone box on the floor of the car, it discharges and blows off the front right of JFK's head. Technically an accident preceded by a suicide attempt.
After Monroe was killed for wanting to marry him, JFK became deeply depressed. That coupled with his back pain and drug dependence caused him to look for a way out of the tragedies emerging in his life.
He had a staffer contact Oswald who had become know with his visits to USSR and Cuba activities. Oswald was the patsy. He fired the first shot into the curb. During the distraction, JFK was planning to kill himself.
He was trying to involve Oswald to make it look like the Cubans so that the country would be angry and declare war against Cuba and possibly the USSR. This is what LBJ later thought the country would want, so he had the Warren Commission go with the lone gunman theory.
I'm working on a book about this.
I can't wait to get your book and find out how Jack Ruby fits in.