Some perspective:
It is not simply a sniper. This is a web of solid repetition. Rehearsal by the collective SS operation.
Comms are set. Spotters are assessing. Snipers are lining up. Again, not simply a sniper.
The quality spotting scopes and glass used by Secret Service is epic. ***We're only speaking 150 yards!
Heck, I'm evaluating individual tines on a deer/elk at a short 150 yards with my commercial brand glass!
There's a primary lead tactical communication command. Any comms for review would immediately be sniper on line and spotters evaluating threat/no threat.
Only possible thought process was an extremely over confident SS team that believed the few buildings present were absolutely secure and protected for restricted access and barred roof access to the point they found it incredibly hard to fathom someone accessed and crawled prone, that it had to be legit...
Then, take into account, no 20 y/o holds the uniform specific markings with an easy to ID semi auto AR that comes to a position pointed towards Trump.
Again. I go back to the simple 150 yards and incredibly visible via spotting to identify the threat...
Even that is absolutely hard to believe. There are designated points and specific locations for Agents. Command leads the comms. Each member has their role.
Example: SA asks, "Where are we going?"??? This is a choreographed and rehearsed process! The location is pre vetted for vulnerable points, staging, placement and securing areas!
This isn't transport security ambushed en-route somewhere (even that is preplanned with action plans). This is a solid site. No moving buildings. It's set for them to own the field.
A 20 y/o just pulled one over on the greatest trained protective service in the world.