Guest Stars Tracy Spiridakos as Detective Hailey Upton Markie Post as Barbara "Bunny" Fletcher Nick Gehlfuss as Dr. Will Halstead Brian Tee as Dr. Ethan Choi Esai Morales as Chief Lugo Chandra West as FBI Special Agent Jennifer Spencer Co Starring Kathy Scambiatterra as Medical Examiner Ruth Dwyer Carmen Bertucci as Carmine Lupino A.C. Smith as Superintendent Darren Stephens as Male White Shirt Elaine Rivkin as Female White Shirt Tom Pettey as Vincent Pollack Christopher Hainsworth as Ted Marchand Tayor Raye as FOP Rep Patrick Cameron as Paramedic