The following excerpt is from In re Barnett, No. 13-15234 (9th Cir. 2015):
(where incarcerated witnesses continued to refuse to testify, court suspended their sentences and held them in civil contempt); United States v. Weinberg, 439 F.2d 743, 745 (9th Cir. 1971) (witnesses still refused to testify after court granted them immunity and ordered them to answer questions). But perhaps such efforts could have worked with at least one of the witnesses.
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