Security at the Capitol

From some more listening and viewing, it seems like the security strategy was something like this:

1) We don't have the resources, preparation, or will to hold them out of the capitol entirely, therefore...

2) Get the officials to safety

3) Set up barricades in narrow places that will be the DO NOT CROSS zones.

4) Let the maniacs come in and roam about and get lost

5) Hold the secondary line until back up arrives and the situation cools down.

The secondary line is where the woman was shot. I watched the video (actually a bit by accident). My biggest thought: it worked. She was trying to breach the secondary line and shooting her made the maniacs stop and retreat.

I suppose GIVEN the situation of being unprepared, the security did their job. No officials were hurt or injured. Of course, the question remains: why were they unprepared?