Two companies, Patullo Modes and Gotham Beef Company, were under investigation by the Bureau of Internal Revenue (BIR) for suspected fraudulent tax evasion. The two companies contacted an attorney who, in turn, conducted negotiations on behalf of the companies with Harry Grunewald (defendant), an “influential” Washington, D.C., insider who agreed, for a large fee, to keep the companies from being prosecuted. Grunewald used his connections and influence with a BIR senior official to obtain “no prosecution” rulings in the two companies’ cases. Thereafter, Grunewald and others worked to conceal their illegal activities and involvement from being discovered. Nevertheless, attempts at concealment failed and Grunewald and two others were indicted on a number of charges, including conspiracy to defraud the United States in violation of 18 U.S.C. § 371. Defendants were convicted and they appealed, arguing that the applicable statute of limitations barred their prosecution. The court of appeals affirmed the convictions. The U.S. Supreme Court granted certiorari to review.