If you’ve seen the slo-mo video, or the still shot of the round going past President Trump’s head, you’ll notice the trajectory was flat. This is not the trajectory a round would take if fired from above the target, it would slope downward. Could there have been a second shooter?
There was another area off site, somewhat grassy with small knoll that could have approximated that trajectory.
No trajectory is flat. The moment a bullet leaves the barrel, it is falling at the same time it is approaching the target.