In the case of Bank of Nova Scotia v. United States (1987), the U.S Supreme Court ruled that a federal court cannot invoke its supervisory power to dismiss an indictment for prosecutorial misconduct before a grand jury, unless such misconduct is prejudicial to the defendant. The Bank of Nova Scotia was indicted on charges related to money laundering and falsifying records but argued that it should be dismissed due to prosecutorial misconduct during grand jury proceedings. However, because these alleged violations did not prejudice the bank's ability to receive a fair trial, they were deemed insufficient grounds for dismissal by both lower courts and ultimately by the Supreme Court in a 6-2 decision.

In the dissenting opinion for Bank of Nova Scotia v. United States, Justice Stevens argued that the majority's decision to uphold a conviction despite acknowledged grand jury irregularities was fundamentally flawed. He contended that such an approach undermined the constitutional role and importance of grand juries in protecting citizens from unfounded prosecutions. The majority had ruled that as long as a defendant could not prove they were prejudiced by these irregularities, their conviction would stand; however, Justice Stevens believed this set an unacceptably high bar for defendants to clear in order to secure their rights under law. Furthermore, he expressed concern over how this ruling might encourage prosecutorial misconduct if left unchecked or unpunished by courts.