In the United States v. Baggot case in 1982, the Supreme Court ruled that the Internal Revenue Service (IRS) could not use a civil audit as a means to gather evidence for potential criminal prosecution. The IRS had audited Robert E. Baggot and discovered discrepancies suggesting tax evasion, which they intended to refer for criminal investigation. However, Baggot argued that this was an improper use of an administrative summons under section 7602 of the Internal Revenue Code because it was issued after his taxes were assessed and he had paid them off - thus there was no longer any "civil" purpose for further inquiry into his records. The court agreed with him in a unanimous decision stating that once assessment is made or jeopardy attaches, then subsequent summonses must be strictly tied to either collection efforts or determining liability for other years' taxes; they cannot be used merely as tools in gathering evidence against taxpayers suspected of fraud.

In the dissenting opinion for United States v. Baggot, it was argued that civil tax audits should not be considered as separate proceedings from criminal investigations. The majority's decision to exclude evidence obtained through a summons in subsequent criminal prosecutions would undermine the effectiveness of IRS investigations and potentially encourage fraudulent behavior. It was also pointed out that there is no statutory basis for distinguishing between civil and criminal matters in this context, nor any compelling policy reason to do so. Furthermore, it was suggested that such a distinction could lead to confusion and inconsistency in future cases. The dissenting justices believed that if Congress had intended such a separation between civil audits and criminal prosecutions, they would have explicitly stated so within the legislation.