So... three options I can think of.

1. Cabal infiltrated security and wanted Trump to be killed.

2. It was staged as part of the movie, and no one was actually hurt (like the Ashli Babbit thing).

3. There was an actual mistake or confusion and that building was left unattended.

Personally, I give #3 a -89% (yes, that is a minus).

The fact that the shooter's last name is Violet and Trump misspelled violence as violent the other day (yesterday?) leads me to hope that it was #2... otherwise, if the Cabal is able to infiltrate the current Secret Service detail around Trump, then the game has changed.