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

What could possibly have changed within that tiny fraction of a second to cause that rear cop's shoulder to look narrower on the right? 

The width of the shoulder is different and so is the angle of it; it's more slanted, more sloped on the left. It's the same cameraman, the same settings, the same position, the same focal point, the same everything. And it's quite a big difference too. That guy on the left was a different man.