Watch : Chicago P.D. This time, instead of taking down criminals and drug lords in the Windy City, the Chicago P.D. "The biggest difference for me is Hailey is this really intense character," Spiridakos told E! "She takes things very seriously and is really focused on what she's doing, whereas Anna is a bit of a wild one." "Hailey's really controlled, she suppresses her emotions to the best of her ability," the 38-year-old explained, "whereas Anna is impulsive.