1. Frank J. Wilson
Chicago mobster and cold-blooded killer Al Capone stayed one step ahead of the law throughout the 1920s despite an annual income from crime estimated at somewhere between US$50 and US$100 million. Enter numbers man for the good guys, accountant Frank J Wilson, who led a Treasury Department investigation into Capone’s tax affairs.
Capone had never filed a tax return or held a bank account, yet some two million records were examined by Wilson and his team. As a gesture of gangster goodwill, Capone took out a contract on Wilson’s life, but the accountant wasn’t deterred. In 1931, Capone was sentenced to 11 years’ imprisonment. A character in the 1987 Academy Award-winning film The Untouchables was based on Wilson.