The guards at the Capitol handled it very well. The amount of casualties is low, could have been much worse.
Indeed. Their primary responsibility during an incident of civil disorder within their limited jurisdiction, such as today's, is to protect the members of Congress, which they did. My impression, as a longtime resident of Washington, is that unlike some of the other agencies that share responsibility for law enforcement in the "monumental core" of the city, the Capitol Police are not trained to disperse a violent mob.
The local Washington police are now fully deployed on the Capitol campus. They have been reinforced by (1) state police from the adjoining states of Maryland and Virginia, (2) agents of the Federal Bureau of Investigation, (3) law enforcement officers of several other, less-well-known federal agencies, and (4) the District of Columbia National Guard—a well-trained military force of civilians (the D.C. equivalent of a "state militia") that is associated with the U.S. Army.
Apropos of which, I was reminded while watching the live TV coverage today of the night of September 11, 2001. My office was three blocks from the Capitol Building. Around 10 p.m., I picked up my brother, who also worked downtown, and we drove back to my house in the northwest quadrant of the city. That was the first time since I arrived in Washington during 1971 that I had ever seen troops in the streets in a non-ceremonial role. Hopefully, once we're finally rid of Trump it will be another 30 years before they need to be called in again.