What is the impact of the panel's ruling that allows a witness not to testify before a grand jury?

The panel's ruling also creates serious problems for the Government in the development of evidence at the grand jury. If the Government calls to the grand jury witnesses other than those who are certain to give testimony helpful to the prosecution (and the Government will frequently prefer to call witnesses of this sort, both to investigate undeveloped matters and to freeze a hostile or wavering witness's testimony), it must then accept admission of their hearsay at trial if offered by the defense, or severely limit its opportunity to prosecute them by conferring use immunity. See United States v. North, 910 F.2d 843, 853-73 (D.C.Cir.1990), cert. denied, --- U.S. ----, 111 S.Ct. 2235, 114 L.Ed.2d 477

Page 626