Barry Pollack was quoted regarding use of the Fifth Amendment to decline to respond to legislative subpoenas for "Bridgegate" documents by associates of NJ Gov. Chris Christie. Some practitioners suggest that Christie's associates should receive use immunity for any testimony or evidence provided due to the subpoenaed documents, indicating that the fact of the production of documents or the provision of testimony to the legislature will not be used against the witness any subsequent criminal prosecution. The target of a subpoena has no incentive to provide documents or testimony without the promise of such immunity and can potentially secure immunity by refusing to comply, Pollack said.
He added that a legislature may not want to grant use immunity when there is an ongoing criminal investigation because it can cause problems for that probe, creating additional complications. "In order for a prosecution to move forward after immunized testimony has been given, the prosecution has to prove the evidence it is presenting is all from an independent source. This is usually difficult," Pollack said. However, there are circumstances where a legislature may still give use immunity, he said. A legislature could confer with prosecutors to determine if a subpoena target will not face charges or if there is sufficient independent evidence. Or, it could want the testimony badly enough that it doesn't care how immunity impacts the criminal inquiry, he added.