US v. Cate, No. 19-30161 (8-21-20)(Tashima w/Fletcher & Rawlinson). The 9th reconfirms that the validity of an underlying conviction cannot be challenged in a SR proceeding. This holds even when the defendant may well be no longer guilty of the underlying offense. The defendant here was on SR because he was a felon in possession. The underlying felony, a third-degree assault, was subsequently determined under the state sentencing scheme to have a stat max of three months; thus, the defendant was not guilty of a felony. US v. Valencia-Mendoza, 912 F.3d 1215 (9th Cir. 2019). The proper vehicle to challenge the conviction is a § 2255 habeas.  The circuits are unanimous on this approach. The 9th then held that the SR sentence was reasonable.

The decision is here:

https://cdn.ca9.uscourts.gov/datastore/opinions/2020/08/21/19-30161.pdf