In the 1981 case Williams v. United States, the Supreme Court ruled that a bank robbery conviction does not require proof of intent to steal from a bank at the time of entry. The defendant, Williams, had been convicted under federal law for entering a bank with intent to commit larceny and robbing it by force and violence. He appealed his conviction on grounds that there was no evidence he intended to rob the bank when he entered it; rather, he made up his mind after seeing how little security there was inside. The Supreme Court disagreed with this argument in an 8-1 decision affirming his conviction. They held that as long as someone forms an intention while still inside a building or structure covered by federal law (like banks), they can be found guilty even if they didn't have such intentions upon initial entry.

In the dissenting opinion for Williams v. United States, Justice Brennan, joined by Justices Marshall and Stevens, argued that the majority's decision to uphold a conviction based on an indictment that did not specify all elements of the crime was in violation of longstanding legal principles. They contended that an indictment must clearly state each element of a crime to provide adequate notice to defendants and ensure they are being tried based on grand jury charges rather than prosecutorial discretion or judicial findings. The dissent also criticized the majority's reliance on "implicit" inclusion of missing elements in indictments as it undermines these protections and creates uncertainty about what is required for valid indictments. Furthermore, they disagreed with applying harmless error analysis in this context because it allows convictions even when constitutional rights have been violated if judges deem errors insignificant enough - something which should be avoided given its potential impact on fair trials.