In the case of United States et al. v. LaSalle National Bank et al., the U.S Supreme Court was tasked with determining whether an Internal Revenue Service (IRS) summons could be enforced when it had been issued after a recommendation for prosecution, but before any formal steps towards prosecution were taken by the Department of Justice. The court held that such a summons could not be enforced if it was solely intended to gather evidence for use in criminal proceedings, as this would violate Fourth Amendment protections against unreasonable searches and seizures. However, they also ruled that if there is still an ongoing civil tax determination or collection process taking place concurrently with potential criminal proceedings, then enforcement may be permissible under certain circumstances.

In the dissenting opinion for United States v. LaSalle National Bank, Justice Rehnquist argued that the majority's decision to allow a summons enforcement action by the IRS after recommendation of prosecution had been made was incorrect. He contended that this ruling would potentially undermine grand jury investigations and could lead to abuses of power by allowing prosecutors to use administrative summonses as an investigative tool in criminal cases. Furthermore, he believed it was not within the Court’s purview to decide on such matters; rather, it should be left up to Congress who has legislative authority over federal tax laws. In his view, once a recommendation for prosecution is made any further investigation should be conducted under grand jury procedures which provide more protections for individuals against potential government abuse.