In Hess v. United States, the Supreme Court ruled in 1959 that a statement made by an individual can only be considered as evidence of guilt if it is clear and unequivocal. The case involved a man named Robert Hess who was accused of conspiring to defraud the government during World War II by selling defective airplane parts. During his trial, prosecutors used statements he had made to investigators as evidence against him - even though these statements were ambiguous and could have been interpreted in different ways. The court decided that this was unfair because it violated his Fifth Amendment rights, which protect individuals from self-incrimination. Therefore, they overturned his conviction on the grounds that any statement used as evidence must clearly show intent to commit a crime.

In the dissenting opinion for Hess v. United States, Justice Brennan argued that the majority's decision was inconsistent with previous rulings and misinterpreted the Federal Tort Claims Act (FTCA). He contended that under FTCA, a federal employee is immune from liability if they were acting within their official capacity when causing harm. However, he believed this immunity should not extend to situations where employees are performing tasks outside of their authority or in violation of regulations. In this case, an army surgeon performed an operation without obtaining informed consent from his patient - a clear breach of medical ethics and potentially military regulations as well. Therefore, according to Brennan’s interpretation of FTCA provisions on discretionary functions exception and law enforcement proviso along with relevant state laws regarding battery by surgeons due to lack of informed consent; it would be inappropriate to grant immunity in such cases because doing so could encourage negligent behavior among government workers while leaving victims without recourse.