Does the use of testimony under the federal immunity statute apply to the prosecution of an immunized witness?

There is potential for semantic confusion surrounding the term "use." The federal immunity statute, like the Fifth Amendment, provides protection from direct and derivative usemeaning that the testimony itself and evidence derived from the testimony cannot be used. In other words, there is no meaningful distinction between the testimony itself and evidence derived from the testimony. Separately, our precedents recognize that certain alleged uses are without constitutional significance. See, e.g., United States v. Mariani, 851 F.2d 595, 600 (2d Cir. 1988) ("To the extent that [United States v. McDaniel, 482 F.2d 305 (8th Cir. 1973),] can be read to foreclose the prosecution of an immunized witness where his immunized testimony might have tangentially influenced the prosecutor's thought processes in preparing the indictment and preparing for trial, we decline to follow that reasoning." (emphases added)).