New York State Troopers Shawn Dean and John Spero had been parked at the side of the highway, driver’s window-to-driver’s window, comparing notes and spooking speeders into slowing down. Dean was content with the notion that everyone was pretty much adhering to the speed limit, if only for the moment. At six o’clock p.m., it was the mid-point of his shift, and Spero’s stint was almost over.