concurring.
I join in full my colleagues’ well-reasoned opinion. I write in concurrence only to alert the district court to consider the potential impact of the Supreme Court’s decision in Alleyne v. United States, — U.S.-, 133 S.Ct. 2151, 186 L.Ed.2d 314 (2013). Alleyne requires that all facts increasing a defendant’s statutory minimum sentence be proved beyond a reasonable doubt. Id. at 2161-63. Because neither party briefed the potential application of Alleyne to this case, on remand the district court is best positioned to consider whether Alleyne’s holding is relevant to Sepulveda’s sentencing under 21 U.S.C. § 841(a)(1) and its attendant penalty provision, id. § 841(b)(1).