The key Supreme Court case involving William W. Hubbell was United States v. Hubbell, decided in 2000. In this case, Hubbell was granted immunity under 18 U.S.C. § 6003 to compel him to produce documents related to a grand jury investigation. The Independent Counsel then used those documents to indict Hubbell on tax and fraud charges. The District Court dismissed the indictment, finding that the evidence used against Hubbell was derived either directly or indirectly from the immunized testimony. The Supreme Court ultimately agreed, ruling that the Government's use of the contents of the produced documents to investigate and prosecute Hubbell violated his Fifth Amendment privilege against self-incrimination. The Court found that the act of producing the documents was itself testimonial in nature, and that the extensive use immunity granted to Hubbell did not permit the Government to make derivative use of the information contained in the documents.