What is the test for severance under Rule 14?

In general, "a district court should grant a severance under Rule 14 only if there is a serious risk that a joint trial would compromise a specific trial right of one of the defendants, or prevent the jury from making a reliable judgment about guilt or innocence.... [T]he determination of risk of prejudice and any remedy that may be necessary [is left] to the sound discretion of the district courts." Zafiro v. United States, --- U.S. ----, ----, ----, 113 S.Ct. 933, 938, 939, 122 L.Ed.2d 317 (1993). The record shows that the district court carefully weighed appellants' allegations that they would be prejudiced

Page 892

"When the reason for severance is the need for a codefendant's testimony," the threshold showing required of the defendant is "(1) that he would call the defendant at a severed trial, (2) that the codefendant would in fact testify, and (3) that the testimony would be favorable to the moving party." United States v. Hernandez, 952 F.2d 1110, 1115 (9th Cir.), (citations and internal punctuation omitted), cert. denied, --- U.S. ----, 113 S.Ct. 334, 121 L.Ed.2d 252 (1992). However, even if this threshold is crossed, a defendant will not necessarily be entitled to a reversal of his conviction. Rather, we have held that, because of "the extremely narrow scope of [appellate] review, ... a moving defendant must show ... that the codefendant's testimony is 'substantially exculpatory' in order to succeed." United States v. Mariscal, 939 F.2d 884, 886 (9th Cir.1991).