Better 2nd shooter theory, with non-retarded evidence: Audio Analysis is 100% Clear: Trump & Crowd Were Shot At By Two Separate People
Summary: the audio for the first 3 shots sounds completely different than the next 5 or 6 shots; there is no echo, it sounds slightly muffled. The first shot appears to have hit the top of the bleachers, slightly above Trump, which suggests an upward angle, not a downward angle. The reports from the gunshots are timed differently, which would only happen if they were fired from (at the very least) different weapons, but probably different distances as well.
Better 2nd shooter theory, with non-retarded evidence: Audio Analysis is 100% Clear: Trump & Crowd Were Shot At By Two Separate People