Whether the term 'controlled substance' in the Sentencing Guidelines is defined at the time of the predicate conviction or when federal consequences attach

QUESTIONS PRESENTED Under the federal Sentencing Guidelines § 2K2.1(a)(4)(A), a defendant previously convicted of a “controlled substance offense” is subject to a sentencing enhancement. The Guidelines define “controlled substance offense” as “an offense under federal or state law *** that prohibits the manufacture, import, export, distribution, or dispensing of a controlled substance.” U.S.S.G. § 4B1.2(b) (emphasis added); see id. § 2K2.1 application note 1. The Guidelines do not, however, define “controlled substance.” In McNeill v. United States, 563 U.S. 816 (2011), this Court confronted the “serious drug offense” enhancement in the Armed Career Criminal Act. According to this Court, to determine the elements of a prior predicate conviction for purposes of applying the categorical approach and thus to determine whether that conviction qualifies as a “serious drug offense,” a court should look to the state law at the time of the predicate conviction. Jd. at 818. The questions presented are: 1. Under this Court’s decision in McNeill, is the term “controlled substance” in the Sentencing Guidelines defined at the time of the predicate conviction or when federal consequences attach? 2. When a federal defendant is subject to a controlled substance enhancement under the Sentencing Guidelines, does the term “controlled substance” in the Sentencing Guidelines refer only to those substances controlled under federal law or also include substances controlled under state law? (i)