Al Capone was a notorious Mafia boss who thrived during the Prohibition era of 1930s Chicago. In the film “The Untouchables,” he was brought down by a small group of gritty law enforcers led by Eliot Ness. The public believed that Ness and his Untouchables were responsible for Capone’s downfall, but that’s not the real story. The Internal Revenue Service recently opened secret documents surrounding the case, including highly classified objects such as Capone’s gun and Ness’s diary. See the full story behind the plot to capture Capone.