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

Look at these images from the SBT reenactments that were tried, some right in Dealey Plaza. Here is something compelling.

Look at that angle! It's about 35 degrees? There is no way that Connally was at the same angle to Kennedy. And note that Dr. Humes estimated the angle of entry in JFK's back as 45 degrees. It was not quite that much, but it was a lot. 

And this Secret Service reenactment proves that the angles just aren't right for it.

A 6th floor shooter would have been shooting sharply downward at Kennedy, but Connally was mostly forward of Kennedy, as you can see here. No way would a bullet go through both of them. 

Yes, that is about 35 degrees, which was much more steep than going from Kennedy to Connally.