It's July 20, 2012. During the midnight screening of The Dark Knight Rises at the Century 16 movie theater in Aurora, Colorado, James Eagan Holmes set off tear gas and shot into the audience. It was the deadliest shooting in Colorado since Columbine. In Part 3 of this three part series, we speak with former Aurora Police Chief Daniel Oates and Denver Division FBI Special Agent in Charge Jim Yacone to talk about the lessons learned for use by law enforcement in future active shooter attacks.