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

Now, Backes is saying could "just as easily" positioned himself over by the wall with the detectives. For some reason, the Idiot put his arrow right where another man was standing, as if Ruby was going to sit on his shoulders. But, let's assume the Idiot meant that he would stand next to that guy. 

First, I don't presume those guys were spectators. I presume they were police. So, you can't assume that Ruby- or anyone- could have placed himself there on that side without somebody objecting. But second, Ruby was toting a gun. If he was next to that guy, a policeman, presumably, that guy would have noticed and interfered. So, why would Ruby go there? Wasn't it better for him to mingle with the journalists on the other side rather than with police on this side if his intent was to shoot Oswald? 

Besides, Ruby did, in fact, approach from the other side. It was his decision. It's not as though it was an accident. He, obviously, thought it was more practical to go at it from that side. 

But second, and more important, is the perspective that Leavelle and Graves had. They came out. They knew there was a wall on their right. They saw all the cops along the wall, most or all of whom they knew. I think they had the perspective that it was safe on that side. What was questionable was the other side with the reporters and cameramen. That's where an attacker could easily position himself without being noticed. 

Here is a diagram of it:

Notice that it says "police guards." So, against the building were police guards, and they were on Leavelle's right. On his left, were where the newsmen were. There's an arrow showing how Ruby was mingling among the newsmen. For the extent of that short walk, the risk definitely was on their left, not their right.