Can a witness be called before he is sworn to testify against self-incrimination?

Thus, it was clear that the government was going to call Dadaian to elicit incriminating information knowing that he would refuse to testify. Where the government intends to call a witness in order to propound incriminating questions, the witness may assert his privilege to refuse to testify. "The rule is well established that the government may not call a witness knowing that the witness will refuse to testify." United States v. Roberts, 503 F.2d 598, 600 (9th Cir.1974), cert. denied, 419 U.S. 1113, 95 S.Ct. 791, 42 L.Ed.2d 811 (1975). Thus, because the government intended to ask incriminating questions and knew that the witness would refuse to testify, it was not necessary for Dadaian to wait until he was sworn before asserting his privilege against self-incrimination.