Twenty-five years ago, cult leader David Koresh entered into a standoff with federal agents that ended in the deaths of 75 people, including his own. A new documentary features survivors and law enforcement officers who experienced the tragedy, and executive producer Charles Poe joins us to talk about how the situation could’ve been handled differently. “Waco: The Longest Siege” airs April 9 at 7 p.m. on Smithsonian Channel.