In U.S. v. Griffith, decided October 10, 2004, the Court held that the information given by the defendant in his pretrial interview could be used against him for impeachment purposes. A pretrial interview is conducted in every case to let the judge know if the defendant is an appropriate candidate for bail. It advises the judge of the defendant’s family background, resident status, employment history, marital status, drug history, length in the country. These Reports are confidential to encourage the defendant to be candid.
But that doesn’t allow the defendant to get up and lie. So if there is material in his Pretrial Services interview that contradicts what the defendant says on the witness stand, the government is allowed to use that information to impeach him. Griffith had testified at trial that he had not used drugs, and that he was a U.S. citizen with a U.S. passport. But to his pretrial officer he had said the he had used drugs and was not a citizen. So the Prosecution took the opportunity to use his Pretrial Services interview against him.
Watch what you say to a probation officer. It may come back to haunt you.