The Taxman Cometh
It may seem like a strange strategy to prosecute a murderer for not paying his taxes. Capone was always able to slip out of any murder indictment against him. Taxation was another matter altogether. Compliance and/or noncompliance with tax laws is kept on record. Back then gangsters didn't think enough to make sure all their flaunted ill-gotten gains were kept on record. In later years they came up with creative ways, including no-show jobs on construction sites, and nonexistent sales positions. But Capone did not have any backup documentation for his extravagant lifestyle.
Most people have heard of Eliot Ness, but fewer folks probably know the name of Elmer Irey. While Ness went to Chicago to try to nail Capone on Prohibition violations, it was Irey who did the paper shuffling and bean counting to catch Capone on income tax fraud. Ness had recruited a team of intrepid fellow agents who could not be intimidated or bribed. They could not be swayed or stopped by the seductive nature of sin or the potential violence against them.
The word untouchable when applied to Eliot Ness and his crime fighters has nothing to do with its more familiar usage, the lowest rung in India's rigid caste system. To be an untouchable in Al Capone's Chicago meant that you could not be bribed or intimidated out of performing your duty.
When the Rat's Away
Al Capone was arrested in Philadelphia for carrying a concealed weapon. He did a little time behind bars. In his absence he left the business in the hands of his brother Ralph and one of his henchmen, Frank Nitti. Nitti took over the administrative duties while Capone was in jail, and he eventually ran things after Capone was sent away for good. Ralph Capone did not have the intelligence, caginess, or business acumen of his brother. He found himself charged with tax evasion. The dogged Elmer Irey had been trying to nail Ralph for a long time. And Eliot Ness had been listening in on Ralph's business dealings courtesy of hidden wiretaps. Ralph was not adept at covering his financial tracks and he was an easier target for the feds than his brother Al.
Hidden in Plain Sight
Ness did more than simply listen in to private conversations. He began to raid Capone's breweries, which were often “hidden” in plain sight. Distilleries were also raided, but most of the hard liquor consumed in Chicago was imported from elsewhere. The Capone mob made its own beer, and there were hundreds of breweries in the greater Chicagoland area. As Sean Connery's character tells Kevin Costner's Eliot Ness in the 1987 movie The Untouchables, “Everybody knows where the booze is. The problem isn't finding it. The problem is, who wants to cross Capone?” Ness was willing to cross Capone. It is estimated that Ness cost Capone over $1 million in spilled beer by seizing and destroying illegal breweries run by Capone. Capone's first response was to try to bribe Ness and the Untouchables; later he tried to kill them.
Eliot Ness's legacy of fighting organized crime in Chicago continued through the activities of William Roemer, a venerable FBI agent who was among the first to use wiretapping against mob bigwigs in the Windy City. Roemer was well known to mob bosses like Sam Giancana and Anthony Accardo. He later recounted his exploits in a series of books about the Chicago Outfit.