In the United States v. Feola case in 1974, the Supreme Court ruled that a defendant can be convicted of assaulting a federal officer even if they were unaware that their victim was indeed a federal officer. The defendants had planned to rob what they thought were drug dealers but turned out to be undercover federal officers. They argued that since they did not know their victims' true identities, they could not have intended to assault a federal officer and therefore should not face charges under the specific statute criminalizing such assaults. However, the court disagreed and held that only general intent to commit an assault is necessary for conviction under this law; knowledge of the victim's status as a federal agent is irrelevant.

In the dissenting opinion for United States v. Feola, Justice Thurgood Marshall argued that the majority's interpretation of 18 U.S.C §111 was incorrect and overly broad. He contended that this statute should only apply when an individual knowingly assaults a federal officer, not simply when they commit assault without knowledge of their victim's status as a federal officer. According to Justice Marshall, such an interpretation would better align with Congress' intent in creating this law - to provide additional protection specifically for federal officers carrying out their duties. The majority’s ruling could potentially criminalize innocent individuals who had no intention or knowledge of assaulting a federal officer, which he believed was unjust and contrary to principles of fair warning in criminal law.