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

Do you realize that the very spot where Oswald was first seen after the assassination proves that he was in the doorway. Look at the map:

Oswald was first seen by Baker coming through the door to the vestibule from the hallway. It means he didn't come down the rear stairs from the 6th floor, and he didn't go up the rear stairs from the 1st floor. He didn't use the rear stairs at all. He came up the other stairs, the front stairs, which only went to the second floor.

If Oswald was in the rear of the building at the time (in the domino room), he would have used the rear stairs, since the snack room was also in the rear. Why walk to the front if there's no purpose in it? But, the fact that he used the front stairs tells you that he was in the front of the building at the time, which is why they were his stairs of choice. 

It was a very different staircase, elegantly decked out, for just the one flight. 

That staircase was in the southeast corner, right next to the doorway. 

There was the doorway, then there was another door behind the glass door, and then around to the right was the staircase that Oswald used. That proves, prima facie, that Oswald was at the doorway. Again, he would not have used those stairs if he came from the back. So, since he was definitely at the doorway, and had to be from what we see above, why would you doubt that he stepped outside? Why the heck wouldn't he? And there is also the original testimony of Carolyn Arnold that she saw him "between the double doors" shortly before the motorcade arrived.