Shortly after midnight on New Year’s Eve, as America’s party city was celebrating the arrival of 2020, a desperate woman on a suburban Las Vegas street leapt out of the back door of a white Hyundai Sonata with a sunroof, and ran toward a front door, chased by the driver of the car. As she charged up the sidewalk, she must have known the chances of anyone being at home at this time, on this night, were vanishingly small. The woman must have felt utterly abandoned as she banged on that door, screaming for help, but no one came to...