Ms. Willis has explained, several times since the assassination, that she looked back at the Book Depository and stopped running because she was following the sound of the first shot.
Rosemary said that she was looking at the pigeons. From Texas Monthly interview with Joe Nick Patoski:
Rosemary: As they made the turn from Houston to Elm Street, they'd just gone a few feet when the first shot rang out, and upon hearing the sound, my normal body reaction was to look up and follow the sound that I heard, it was so abrupt. I didn't know what it was, but I was looking for what I heard. And the pigeons immediately ascended off that roof of the school book depository building and
that's what caught my eye. My eyes were searching for what I heard and I see the pigeons, you know, they're scared to death, and take off in abrupt flight. Next thing I know, right after that, there's another shot. And after that, there's another shot and another shot. We disagree, between me and her (nodding towards her mom and sister).
My ears heard four shots. If you ask me how many I think there were, I really think that there were six, but I heard four and I'll tell you why: the first one, you know I'm right across from Zapruder. I'm wherever the limousine is. It's almost like I could...I'm right there. Anyway, the first shot rang out.
It was to the front of me, and to the right of me, up high. The second shot that I heard came across from my right shoulder. By that time, the limousine had already moved further down. And that shot came across my shoulder. And the next one, right after that, still came from the right but not from as far back, it was up some. Still behind me, but not as far back as the other one.
And the next one that came was from the grassy knoll and I saw the smoke coming through the trees, into the air.... Fragments of his head ascended into the air, and from my vision, focal point, the smoke and the fragments, you know, everything met. I mean, there's no question in my mind what I saw or what I heard.
