My question is, what did the Biden Administration know about it and when? Every other shooter in recent history was "known to the police". I'm sure this one was as well. The fact that there was no one on that roof and no one stopped this guy beforehand, and all the nonsense stories they keep coming up with all indicate that the administration likely knew something was going to happen, and planned the actions of SS and local law enforcement to facilitate the event.
According to reports, they found an IED in his car and a transmitter and cell phone next to his body. I believe he had planned on an explosion as a distraction, but when he found he could get to the roof and no one was there, he just went with it. I don't know anything, so that's pure speculation on my part.
Neither does the Secret Service, so you are not alone.