If you ad normal eyesight and a functioning brain, then you would not doubt that there were seven red rings on the windows on the south side, upper floor windows at the time President Kennedy was ambushed and murdered ......
And this, of course, means they were signals to LBJ! We can ignore Gary Mack's explanation and newspaper accounts from years earlier indicating that these were used for fire safety and instead take your word for it. I can write some dialogue for your fictional book:
LBJ: "Now Lady Bird, if you see a red ring on yonder building get your sweet self down because they gonna be some shooting!"
Lady Bird: "Which building?"
LBJ: "Yonder woman." Bang, bang, bang. "Hot damn."