According to published reports, in a recent local case, a witness said he had evidence to show that a man charged with homicide is innocent. The District Attorney's office didn't believe he was telling the truth and and refused to grant the witness immunity.
The judge said he has no authority to grant immunity to a witness. He said there wasn't a reason why the Allegheny County District Attorney's Office was withholding immunity.
The DA had the witness under subpoena and the witness invoked 5th Ammendment priveledges to refuse to testify. Because the witness would not testify, the Judge said the Defendent in the case would not receive a fair trial. He dismissed the case. The commonwealth has appealed that.
Bruce Antkowiak, an Assistant professor of Law at Duquesne University says this case is not the norm. In federal courts, a judge can either grant immunity to a witness or force a prosecutor to do it. This issue has come up previously he said. He is not connected to the case in any way.