In Scott v. United States the Ninth Circuit, sitting en banc, held that established principles governing the retroactive operation of new constitutional decisions demanded a full retroactive application of Leary v. United States, in which the Supreme Court declared unconstitutional a federal statutory presumption permitting the trier of fact to infer "knowledge of importation" from the mere fact of possession of marijuana.
Stephen A. McFeely,
The Retroactive Reach of Leary v. United States,
22 Hastings L.J. 873
Available at: https://repository.uchastings.edu/hastings_law_journal/vol22/iss4/4