The drone hovered over the clearing in the wooded park on Staten Island, the thin cord that tethered it to the ground unspooling enough for it to fly above the trees. Michael Wall, a New York City firefighter, stood on the ground below, operating the drone from a portable command center of sorts, with controls and a monitor housed in a mustard-colored case. He adjusted a joystick to point the drone’s camera toward New Jersey. A clear shot of the Bayonne Bridge filled the screen in front of him. He panned the camera over the park, sweeping the shot over the dogs that paused from their play to look up and bark, and then zoomed in for a view of the back of a white house across the street.