Instead of advising residents to stay out of the area in which they...reside, why don’t police ever tell feral punks to stay out of residential (and retail) areas?
Police also shut down the Oakland 12th St BART station because they were searching for the shooter and suspected he was on a train from San Bruno. Feral youth sometimes use BART to get to peninsula destinations (richer targets) from Oakland to do mayhem. The San Bruno BART station is attached to the San Bruno Tanforan Mall (and is next to a police station so response is rapid).