the assassination attempt seems to have brought out it own onset of online crazy. I assume that the situation will be evaluated and directives made to try an avoid whatever mistakes were made. I also assume they will not be made public(?)
Some people seem to have a hard time with the assigning varying degrees of responsibility
Was the building supposed to be secured? Why or why not? - Yes, very much so
Who was responsible for securing it? - Sounds like county/local police had that responsibility as it was outside the secured perimeter
What happens when one element does not fulfill its responsibility? - Depends on whether the bad guy is lucky or skilled enough to capitalize. Usually nothing, but in this case very nearly the supreme act of political violence.
I get that the USSS is ultimately responsible. But was the USS CS team supposed to redeploy, if in fact the building roof was supposed to be manned? - Sounds like no; county/local SWAT were supposed to be up there, whether counter-sniper suspiciously or just some sort of presence.