Okay I’m back in NoVA.
OS stuff:
Trump as a candidate gets a personal security detail, as a former POTUS he gets PPD (Presidential Protection Detail) which is larger than what a candidate would have, he also had a CAT team and a CS team (the two dudes on the roof).
Now having done the two dudes on a roof thing before, there is only so much that 2 guys can watch (as one is supposed to be the primary shooter on the rifle at all times, and the other is doing observation) for POTUS there are more than one CS team. I won’t get into CS stuff beyond that, two of my co-workers are former USSS CS.
Venues: Depending on the size of the venue and the size of the detail, a lot of internal and all the external areas are left to be watched by State Police, Other Fed LE and local LE, as well as UD and Agents from the local (or local ish) USSS field office - many of the non PPD, CAT and CS have limited to no tactical training.
CS will ideally have had a shooter on the advance to do some prep work, but I don’t know if this team had that option, and may have been brought in with CAT just prior and gotten a brief from the PPD agent on the advance —
PA is one of many states that allows for open carry of rifles, so some dude with a rifle (or a bunch of guys with rifles) outside the venue isn’t going to be shut down, sure you would watch them — but one also needs to remember that a lot of MAGA folks show up to these in camo and rifles - former President Trump isn’t going to let any LEO’s inc the USSS screw with his supporters exercising their legal rights to firearms possession.
Having had to deal with that as a LEO in the past, I can tell you it is what it is, 99.999% of firearm owners are LE supportive and law abiding folks, so one has to be cognizant of that fact, but a good friend of mine reminded me years ago - there is a gun at every call I go to, mine. Meaning that any situation has the potential to escalate due to one’s own service weapon, and so it’s a nature of the business aspect and one needs to deal with it. If I get stopped there is a 99.99% I’m armed, so I’m polite and inform the officer that I am armed - I’ve yet to had a problem from that outside of an incident several years ago at a State Police barracks when a young trooper apparently figured the machine gun, suppressor and gear I had was for nefarious purposes despite me asking where the Tac Team Sgt I was supposed to meet up with was. He ended up having a really shitty day when the Major running NJ SWAT came out to see me and lost his mind that I was being accosted by a patrol trooper.
/ tangent
At the end of the day the FBI, USSS, and many other organizations are going to conduct a very thorough AAR on this incident. As it was a high profile shooting by Fed LEO’s involving a fatality, the FBI will also investigate that aspect separately.
Wrapping one’s tinfoil too tight isn’t going to help anyone.