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

There is a lot available on Zapruder film alteration, but this is my favorite video series about it on youtube.

https://www.youtube.com/watch?v=5Am4qdl9PTA


Here is another one which features Doug Horne talking about it.

https://www.youtube.com/watch?v=AVaGYxuPQg8

Here is another one which features John Costella:

https://www.youtube.com/watch?v=3Y6RaDmG0hs

Here is another which features Jack White:

https://www.youtube.com/watch?v=dvLW3IBHHvA

Here is another one by Greg Burnham:

https://www.youtube.com/watch?v=L_JGh30idHw

Here is another with Doug Horne and Dino Brugioni

https://www.youtube.com/watch?v=VoJ7tikaGBE


And there are plenty more. It is very widely recognized and respected by leading JFK researchers that the Zapruder film was altered.