The IRS caught Al Capone for tax evasion by ignoring his violent crimes entirely and going after his money. Treasury agents spent years documenting his spending, seized a gambling ledger that tied him to hundreds of thousands of dollars in profits, and used an indirect accounting technique to calculate what he owed without ever seeing a tax return from him. In 1931, a jury convicted him on five counts, and a judge sentenced him to eleven years in federal prison.
The Supreme Court Ruling That Made the Case Possible
Before any of the accounting work could matter, prosecutors needed a legal answer to a basic question: is money earned from crime taxable at all? The Supreme Court settled that in 1927 in United States v. Sullivan, a case involving a bootlegger who refused to file a return on the theory that reporting illegal liquor income would violate his Fifth Amendment right against self-incrimination.1Cornell Law Institute. United States v. Sullivan, 274 U.S. 259 (1927)
Justice Holmes rejected the argument. A taxpayer, he wrote, “could not draw a conjurer’s circle around the whole matter by his own declaration that to write any word upon the government blank would bring him into danger of the law.” The federal power to tax income “from any source whatever” meant what it said. A criminal could decline to specify the illegal activity on a return, but he could not decline to report the income. That single distinction opened the door for everything the government later did to Capone.
Tracking Spending and Cracking the Gambling Ledger
The financial investigation ran through the Treasury Department’s Intelligence Unit, the forerunner of today’s IRS Criminal Investigation division. Special Agent Frank Wilson, working under chief Elmer Irey, led it. The obstacles were significant: Capone had filed no returns for 1924 through 1929, kept no bank accounts in his own name, ran no visible business, and dealt almost entirely in cash.2Wikisource. Summary Report of Al Capone for the Bureau of Internal Revenue (1933)
Wilson’s team worked the case from the outside in. They pulled records from department stores, jewelers, car dealerships, and hotels. They documented custom-made clothing, diamond-studded accessories, and a Miami Beach estate bought through an intermediary. They found telephone bills totaling $39,000 and evidence of expensive entertaining. None of this proved a criminal enterprise. It proved something more useful for a tax case: a man with no reported income was spending like a millionaire.
The breakthrough on the income side came from three bound ledgers seized in a 1926 raid on one of Capone’s Cicero gambling establishments. The ledgers had columns for “Craps,” “21,” and “Roulette,” with profits divided among “Town,” “Ralph,” “Pete,” and “A.” Investigators matched the handwriting to Leslie Shumway, the cashier at the Hawthorne Smoke Shop, by comparing it against deposit slips at a local bank. Shumway eventually cooperated, testified that he took orders directly from Alphonse Capone, and estimated the operation’s profits exceeded $550,000 over two years.
A second cooperating witness, Fred Reis, admitted he had been the named payee on numerous large cashier’s checks representing Capone’s net profits from the Cicero gambling hall. He put the hall’s 1927 profits alone at roughly $150,000. The government also obtained the “Mattingly letter,” in which Capone’s own tax attorney had conceded taxable income for the disputed years, running from $26,000 in 1924 to $100,000 in 1928 and 1929. That concession, from the defense side of the table, was one of the more damaging documents in the file.
The Net Worth Method: Building a Tax Bill Without a Return
With no returns and no corporate books, prosecutors needed a way to translate scattered evidence into a specific dollar figure. They used what the IRS calls the Net Worth and Expenditures Method, an indirect technique built for taxpayers who keep no records or hide the ones they have.3Internal Revenue Service. 9.5.9 Methods of Proof – Section: 9.5.9.5 Net Worth Method of Proof
The idea is simple arithmetic. Agents calculate the target’s assets minus debts at the start of a year, then do it again at the end. Any increase in net worth had to come from somewhere. If the taxpayer cannot show a non-taxable source such as a gift or inheritance, the IRS treats the increase as taxable income. Personal spending during the year is added on top, because money spent on living expenses also came from somewhere.4Internal Revenue Service. Examination of Income – Section: 4.10.4.5.7 Net Worth Method
For Capone the numbers were brutal. Agents established a low starting net worth and then documented major increases in assets alongside enormous personal expenditures. The Miami Beach property, the ledger profits, the cashier’s checks, the receipts from luxury purchases — every piece fed the calculation. The gambling ledgers gave direct proof of specific income for 1925, 1926, and 1927; the spending records covered the full period. The gap between zero reported income and a life that plainly cost hundreds of thousands of dollars was the case.
The Indictment, Trial, and Sentence
A federal grand jury in Chicago indicted Capone on June 5, 1931, for willfully attempting to evade income taxes for 1925 through 1929 and for failing to file returns. The indictments combined felony evasion counts with misdemeanor failure-to-file counts, and the court consolidated them into a single trial. Capone’s lawyers challenged that consolidation on appeal and lost.5Justia Law. United States v. Capone, 51 F.2d 609 (7th Cir. 1931)
Capone initially tried to plead guilty in exchange for a lenient sentence. When Judge James H. Wilkerson refused to promise anything, Capone withdrew the plea and went to trial. The proceedings ran about two weeks in October 1931 under heavy press coverage.
On October 17, 1931, the jury returned guilty verdicts on five counts: three felony counts of tax evasion for 1925, 1926, and 1927, and two misdemeanor counts of failing to file returns for 1928 and 1929. He was acquitted on the remaining counts. Judge Wilkerson sentenced him to eleven years in federal prison and ordered him to pay $80,000 in fines and court costs.6National Archives. Exhibit: Al Capone Verdict The man who ran Chicago’s underworld had been taken down by accountants working from receipts and a bookkeeper’s ledger.
Why the Same Approach Still Works
The strategy that convicted Capone wasn’t a one-off. The net worth method remains one of the IRS’s standard indirect techniques for reconstructing income, and the Sullivan rule that illegal income is taxable has been reinforced ever since.4Internal Revenue Service. Examination of Income – Section: 4.10.4.5.7 Net Worth Method7Office of the Law Revision Counsel. 26 USC 61 Gross Income Defined8Internal Revenue Service. Publication 17 (2025), Your Federal Income Tax The Fifth Amendment argument Sullivan tried has been tested repeatedly and lost each time; a blanket refusal to file is treated the same as never filing at all.
Capone’s real lesson for federal prosecutors was that the hardest-to-hide part of a criminal enterprise isn’t the crime. It’s the money that comes out the other end.