Taylor (defendant) and Neff were charged with criminal counts relating to their alleged involvement in an armed robbery. The United States (plaintiff) offered statutory use immunity to Neff in exchange for his truthful testimony before a grand jury. During Taylor’s trial, the prosecution informed the court that it had decided to revoke Neff’s use immunity after receiving information that Neff had perjured himself before the grand jury. Neff’s attorney informed the court that Neff intended to invoke his Fifth Amendment privilege against self-incrimination if called to testify at Taylor’s trial. Taylor’s attorney moved the court to compel the prosecution to grant Neff use immunity and argued that the prosecution’s sole motive for revoking immunity was to prevent Neff from providing testimony favorable to Taylor. The prosecution asserted that it intended to indict Neff. The court declined to compel the prosecution to extend use immunity upon a finding of no indication of bad faith on the part of the prosecution. In light of Neff’s assertion of intent to invoke his Fifth Amendment privilege against self-incrimination, the trial court deemed Neff to be an unavailable witness pursuant to the Federal Rules of Evidence. In accordance with the Rules of Evidence, the trial court allowed Taylor to introduce excerpts from Neff’s grand jury testimony in lieu of Neff’s personal testimony. On appeal, Taylor argued that the prosecution had abused its discretion by revoking Neff’s immunity and that the trial court deprived him of a fair trial by refusing to compel immunity.