As he rushed his family to the hospital, 26-year-old NFL running back Ryan Moats rolled through a red light. A Dallas police officer pulled their SUV over outside the emergency room. Moats and his wife explained that her mother was dying inside the hospital. "You really want to go through this right now?" Moats pleaded. "My mother-in-law is dying. Right now!" The officer, 25-year-old Robert Powell, was unmoved. He spent long minutes writing Moats a ticket and threatened him with arrest. "I can screw you over," the officer told Moats. "I'd rather not do that." The scene last week, captured...