Manuscripts and records used in the course of this research book are located in scattered federal agencies or private collections. To save space in the notes, I have abbreviated references to records as follows: (DOT-ATF) Al Capone records, Department of the Treasury, Alcohol, Tobacco, and Firearms Unit; (DOJ-Tax) Al Capone records, Department of Justice, Tax Division; ( FBI) Al Capone records, Department of Justice, Federal Bureau of Investigation; (FS-HHPL) French Strother papers, Herbert Hoover Presidential Library; (HHPL) Herbert Hoover Presidential Library; (MWW-FBI) Mabel Walker Willebrandt records, Federal Bureau of Investigation; ( BOP) Sanford Bates records, Department of Justice, Bureau of Prisons; (SHSU) Sanford Bates records, Sam Houston State University; and (WDM-MHS) William D. Mitchell records, Minnesota Historical Society. Litigation was brought against the Internal Revenue Service in 1986 to open the IRS tax investigation records of Alphonse Capone. The United States Court of Appeals (5th Circuit) ruled, however, to permit the government continued secrecy over records more than sixty years old for a deceased and convicted federal felon. See J. D. Calder, "Al Capone and the Internal Revenue Service: State-sanctioned Criminology of Organized Crime", Crime, Law and Social Change 17 ( April 1992): 33-46.