Larry, the incident of Thomas Arthur Valet in Chicago was ample warning enough of some plot underway
besides all the bumper stickers and the JFK “traitor” pamphlets from such anti Kennedy persons known by FBI and actually recorded predicting the method of disassembled rifle from high building window
As well as the known FBI surveillance of Oswald and the Hosty note from Oswald that was coincidentally destroyed
As well as Hosty feigning ignorance of the motorcade route let alone prior knowledge that Oswald the defector was currently employed in TSBD
As well as a high probability that George DeMorensheild knew of the MC rifle Oswald had and likely also deduced that Oswald had shot at General Walker
The breaking of SOP for Secret Service to ride on the JFK limo and LBJ ducking before shots are fired
The mistress recount of the secret LBJ meeting the night of Nov 21/63
The reversal of JFK foreign policy concerning Vietnam by LBJ only 3 days after the assassination
The owner of the TSBD , Harold Byrd, close friend of LBJ, receives billion dollar contract to build A7 fighter/bomber planes to be deployed in the Vietnam “new policy” ie: 180 000 boots on ground
Gulf of Tonkin fake red flag event
The “ Wink” photo of LBJ beside the grieving Jackie Kennedy with the blood still on her dress
And this all before even getting into the Joint Chiefs of Staff and General Curtis LeMay
And before even the issue with the Mafia boss whom JFK had kidnapped and dropped into SA jungle whom managed to survive, returned to USA and vowed to “ cut off the head of the snake
Connected therefore to Jack Ruby who is connected with Oswald
IDK for certain,Larry, but IMO, these “Coincidences” add up to a high probability of many persons with pre knowledge of a Dealey Plaza attempt to be made and some of them, like Jack Ruby, And LBJ were there