In the United States v. Reshat Shabani case of 1994, the Supreme Court unanimously ruled that proof of an overt act is not necessary to convict someone under federal conspiracy law. The defendant, Reshat Shabani, was charged with conspiring to distribute cocaine and argued that his conviction should be overturned because there was no evidence he committed any overt act in furtherance of the conspiracy. However, Justice O'Connor wrote for the court stating that Congress deliberately omitted any requirement for an overt act from this specific statute (21 U.S.C §846), unlike other federal conspiracy statutes which do require such acts as part of a conviction. Therefore, it was decided that merely entering into a mutual agreement or understanding to violate drug laws constitutes a crime itself under this particular law.

In the United States v. Reshat Shabani case, there was no dissenting opinion recorded. The Supreme Court ruled unanimously in favor of the government's interpretation of federal law regarding conspiracy charges in drug cases. Justice Sandra Day O'Connor delivered the opinion for a unanimous court, stating that proof of an overt act is not necessary to convict someone under the federal drug conspiracy statute (21 U.S.C § 846). This decision clarified that Congress intentionally omitted this requirement from its legislation and thus it should not be read into it by courts.