Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

Now I have compared the phony arrangement in the Zapruder film with the real one in Dealey Plaza. Notice in the top photo that you can see the cars on Houston Street which haven't even turned yet. The idea that the sign was that close to the intersection is ridiculous. Then, in the bottom photo, the sign is circled, and there is a red swath that represents the part of the Zapruder film that they cut out. And their cutting it out is why the limo gets to the sign so fast in the Zapruder film. 

Why did they cut it out? They cut it out because JFK was shot in the back high on the hill, and he was reacting to it. It was a strange reaction because it was a strange shot: an ice fleschette containing a nerve agent. As the drug seeped into his system, his mind started shutting down and his muscles started seizing up. It was meant to immobilize and incapacitate him so that he would be a sitting duck once the limo entered the Kill Zone.