Al Capone was guilty of numerous felonies, but proving the charges appeared to be beyond the power of the US government. However, Capone's theory that "The government can't collect legal taxes on illegal money" proved ineffective when, in 1931, he was convicted of, and sent to prison for, income evasion. Joseph Daly Nunan, Jr., commissioner of the IRS from 1944 to 1947, had a similar awakening. In 1948, Nunan won an $1,800 bet on the outcome of the presidential election of Harry Truman. This income, along with an additional $90,000 of income, was not reported on his tax returns. Nunan was convicted of income tax evasion in 1952.

Al Capone was guilty of numerous felonies, but proving the charges appeared to be beyond the power of the US government. However, Capone's theory that "The government can't collect legal taxes on illegal money" proved ineffective when, in 1931, he was convicted of, and sent to prison for, income evasion. Joseph Daly Nunan, Jr., commissioner of the IRS from 1944 to 1947, had a similar awakening. In 1948, Nunan won an $1,800 bet on the outcome of the presidential election of Harry Truman. This income, along with an additional $90,000 of income, was not reported on his tax returns. Nunan was convicted of income tax evasion in 1952.