Okay so it might not be constitutional law, but it should just be common sense to go and call in backup when people are under attack!!
It is obvious you speak from an emotional standpoint, however emotions are irrelevant in matters of Law.
Society has become indoctrinated, that emotional feelings, should supersede the Law.
The Lawful Jurisdiction on the Capitol Building and Grounds is the Congress. It was THEIR duty to provide adequate Security and Call for any necessary reinforcement.
Did they?
The DC Chief of Police had security in place, and his superiors (Congress Authority), dictated to send the extra security officers home!
The same Authority (Congress) refused Trumps Offer for Military Security support, while the Congress would be convened.
Do you know "who specifically" is the Congressional Authorative Mouth piece...
That CAN Request or Reject any number of Security guards at any given time?
You Should know...it's the peacock that struts in Congress, holds the Gavel, holds the Pen, claims the Podium, the Microphone, it's her temple.
So if you are upset...why not Point your finger at Who's LAWFUL DUTY it was to have adequate security and Call in reinforcements When her incompentence to be prepared failed?