The Menninger book gives an explanation for why no one saw the AR-15 fire: it had a flash suppressor on the tip of the barrel, making a firing impossible to see unless at night or near-dark. The assassination took place in broad daylight, almost at high noon, so the flash would have been invisible.
The AR-15 of 1963 was known, however, for making a “plume of smoke,” as McLaren points out. Plenty of witnesses saw “a puff of smoke,” although their accounts of where the smoke came from differ. Smoke is not easy to focus on. If their accounts could be “triangulated,” I have no doubt that the source would be shown as the follow-up car.
What is most interesting is the number of witnesses who Hickey with the rifle right around the time of the third shot, that he “popped up” out of nowhere. Some witnesses thought that he had “returned fire.” The McLaren book gives the actual eyewitness accounts.
