And it just so happens that several people saw a sniper either shoot from that window, saw a rifle or what looked like a rifle being retracted from the window, three witnesses who were one floor below hear shots coming from right above them one of which heard the distinct sounds of shells hitting the floor above him and of the rifle bolt being operated. That's called a mass imaginary illusion. The one who is imagining is that one who refuses to accept that there was actually a sniper in the SN shooting at JFK.
Then you should be able to answer a question
Watch the part of the Robert Hughes film where the Presidential motorcade is turning onto Elm Street from Houston Street. Right before the film cuts-out from that view, we can see Kennedy's limo is fully around the corner and now on Elm Street. At this point, we also see the southeast 6th-floor window. Unfortunately, the film cuts-out and you are unable to see a person or gun like some described to have witnessed. Now take all of the witnesses who say they saw someone in the window with a gun.
Of those witness accounts, Howard Brennen seems to have had a direct view and describes it as: "this man the same man I had saw prior to the president's arrival was in the window and taking aim for his last shot after he fired last or the third shot of he didn't seem to be in a great rush hurry he seemed to pause for a moment to see if for sure he accomplished his purpose and he brought the gun back to a resting upright position as though he was satisfied."
Brennen seems to say he saw a man with a gun in the window and firing the gun out of a window ---before, during and after.
The question for you is: In the Hughes film at the very last point where you can see the 6th-floor window at the same time the Kennedy limo is fully around the corner on Elm Street, how long would you say it is before the man could be seen with a gun
in the window?