Just as JFK's limo was coming into the crossfire zone, the guy on the grassy knoll pumped the umbrella up and down a couple of times.
The guy in the storm drain gets into position, raises the rifle, and shoots twice, then beats cheeks out of there through the storm drain.
One finds this a much better explanation of what happened than the Warren Report. It was on the X-Files. :)
“Beat cheeks out thru the storm SEWER.”