I'd like to help! What is the method to detirmine that archival footage is "authentic"? Looks real to me and, if you watch Kellerman and Greer in the Zapruder film, which the US Government accepted as authentic, you can clearly see both of these individuals abandoning JFK. Kellerman was specifically assigned as his body guard and was required to shield JFK with his body. Johnson's SS agend did when the shooting started. Instead, Kellerman saw JFK was hit and then simply turned back around and sat there. Greer turned back TWICE as everyone in the limo was visibly in distress. His second turn sure looks unusual for someone who is trained to keep both hands on the wheel! To me it looks like the Adams / Newcomb / Cooper / Robertson observations are correct and the stabilized Zapruder showing Greer turning back to fire a pistol (low near his lap and NOT near Kellerman's forehead) is the evidence hiding in plain sight. Could the shooters have been blowing it and was Greer forced to finish the job?