Is there a judicial remedy for the referral of an allegation of sexual assault to federal authorities?

In appellant's reply brief, he argues for the first time that the referral of his prosecution to federal authorities violated his due process rights, not because the charging decision was arbitrary or capricious, but because it deprived him of the benefit of his plea agreement. We do not decide whether a judicial remedy would exist for such a violation, however, as appellant has waived the issue by failing to raise it in his opening brief. United States v. Bentson, 947 F.2d 1353, 1356 (9th Cir.1991), cert. denied, --- U.S. ----, 112 S.Ct. 2310 (1992).