When seconds count, as Glenn Reynolds is wont to say, the police are only minutes away....

Money quote from Paula Bolyard:

I realized at that moment that the police cannot protect me from the Dzhokhar Tsarnaevs of the world.
The best they can do is tell me to lock myself in my home while they search for the bad guy. Though the residents of Watertown (and the surrounding greater-Boston area) were held in a state of near-martial law, the best most of them could do was huddle in their homes, hoping the police would take their 3 a.m. call and come running to rescue them before the terrorist killed them. . . . I realized right then that if I were holed up in my house while a cold-blooded terrorist roamed my neighborhood, I wouldn’t want to be a sitting duck with only a deadbolt lock between me and an armed intruder.

Neither, as Dr Reynolds said, would I.