In the 1951 case Casey et al. v. United States, the Supreme Court ruled on an issue related to tax evasion and fraud. The defendants were accused of evading taxes by falsely declaring their income from illegal gambling activities as legitimate business earnings. They argued that they should not be prosecuted for tax evasion because doing so would indirectly punish them for illegal gambling, which was a state offense rather than a federal one at the time. The court rejected this argument, ruling that even if income is earned through illegal means, it must still be reported accurately to the Internal Revenue Service (IRS). Therefore, regardless of whether or not their primary activity was legal under state law, they had committed a separate federal crime by falsifying their tax returns in order to evade paying taxes on these earnings. This decision affirmed that all individuals are required to report all sources of income honestly and accurately when filing their taxes with IRS irrespective of how such incomes were generated.

The dissenting opinion in the case of Casey et al. v. United States disagreed with the majority's interpretation of Section 2(c) of the Emergency Price Control Act, arguing that it did not provide a basis for criminal prosecution for violations of rent regulations issued under its authority. The dissent argued that this section was intended to apply only to price controls and not to rent regulations, as these were covered by separate legislation - namely, the Housing and Rent Act. They contended that interpreting Section 2(c) as applying also to rents would render certain provisions in the Housing and Rent Act redundant or meaningless, which is contrary to principles of statutory construction. Furthermore, they pointed out inconsistencies between penalties provided for in both Acts – while violation of price control could result in imprisonment up to one year or fine up $10k or both; violation under housing act could lead only upto $5k fine without any provision for imprisonment.