Ninety years ago this week, one of the most horrifying acts of violence in organized crime history occurred inside a nondescript garage at 2122 North Clark Street in Chicago. On the morning of February 14, 1929, seven members of George “Bugs” Moran’s North Side bootlegging gang were lined up against a brick wall and shot dead. The perpetrators were never prosecuted, but few people then or now doubt that Al Capone’s Outfit was behind what the press called the St. Valentine’s Day Massacre. There had been a whole lot of shooting between Chicago’s rival Irish and Italian bootleggers during Prohibition, ...