The federal controlled substances list mistakenly failed to renew the listing of two drugs. Benzylfentanyl and Thenylfentanyl continued to be listed on the federal controlled substances schedules from 1986 to 2010 even though their designation had expired. (See 75 Fed. Reg. 37300-301 (June 29, 2010).) These substances, however, continued to be listed on the Connecticut controlled substances schedules for this entire period, and the same is likely true for other states as well, based on the federal error. This gives rise to the argument that the Connecticut (and perhaps other states) controlled substances lists contained at least some drugs that were not listed on the federal schedules, so the Connecticut controlled substances offenses are not a categorical match with the federal controlled substances offenses for immigration purposes. Since there is no categorical match, the courts must use the modified categorical analysis. If the record of conviction does not establish which drug on the state list was involved in the case, then the state conviction does not trigger deportation because the government bears the burden of proof.
Thanks to Michael Boyle.