This concerned the Mall and the parade route ~ with several thousand cops prepared to instantly leap into action.
The temperature (30 degrees F) and the wind (25 MPH) helped keep the crowd quiet.
I was listening to the police on the Mall and the parade route. There were also lots of lost kids, old people with breathing problems, and various medical problems - seizures, diabetic issues, etc. The location of the trouble makers they chased and then let go was the Mall and the parade route.