NB: This post is predominantly US focused. The most interesting part for US Analogue Act prosecutions is the document in footnote 1.
tl;Dr: Analogue act is scientifically vague[1], and ignorance of the law is potentially a defense when a legal element is part of the definition of the offense.
The current Synthetic Drug Law is woefully inadequate, as written, and has lead to the false imprisonment of hundreds of men and women throughout the United States.
A case from Syracuse, N.Y. will soon be decided by a 3 judge panel in the Second Circuit Court, Manhattan, N.Y. In that case, William Harper, a former Syracuse businessman, and 22 others were arrested for Conspiracy to Possess and Distribute a Controlled Substance Analogue, 4-Methylmethcathinone (4-MMC) and 4-Methylethylcathinone (4-MEC), both colloquially known as Molly. Harper is currently serving an 84 month sentence in Lewisburg, PA, one of America's harshest Federal Prisons.
Harper and the 22 others may actually have been innocent according to nine established forensic expert scientists and the National Association of Criminal Defense Lawyers. Two briefs, [1][2] submitted by the foregoing to the Supreme Court in McFadden vs. USA, spell out exactly why the law is inadequate in its verbiage and definitions; ensnaring people who believe their behavior is lawful. In the unanimous 9-0 decision favorable to McFadden and against the Government, Chief Justice John Roberts wrote some interesting thoughts you can read here: https://www.washingtonpost.com/news/volokh-conspiracy/wp/2015/06/18/ignorance-of-the-law-is-no-excuse-or-is-it/
Some relevant extractions from that article:
Section 841(a)(1) makes it "unlawful for any person kmowingly ... to manufactureAs the Court points out, the word "knowingly" applies "not just to the statute's verbs, but also to the object of those verbs--'a controlled substance.'" That suggests that a defendant needs to know more than the identity of the substance; he needs to know that the substance is controlled.
In cases involving well-known drugs such as heroin, a defendant's knowledge of the identity of the substance can be compelling evidence that he knows the substance is controlled. But that is not necessarily true for lesser known drugs. A pop quiz for any reader who doubts the point: Two drugs--dextromethorphan and hydrocodone--are both used as cough suppressants. They are also both used as recreational drugs. Which one is a controlled substance?* [FN*: The answer is hydrocodone.]
The Court says that knowledge of the substance's identity suffices because "ignorance of the law is typically no defense to criminal prosecution." Ante, at 5. I agree that is "typically" true. But when "there is a legal element in the definition of the offense," a person's lack of knowledge regarding that legal element can be a defense. Liparota v. United States, 471 U. S. 419, 425, n. 9 (1985). And here, there is arguably a legal element in Section 841(a)(1)-- that the substance be "controlled."
The analogy the Court drew in Liparota was to a charge of receipt of stolen property: It is no defense that the defendant did not know such receipt was illegal, but it is a defense that he did not know the property was stolen. Here, the argument goes, it is no defense that a defendant did not know it was illegal to possess a controlled substance, but it is a defense that he did not know the substance was controlled.
[1] https://archive.org/download/McFaddenBriefs/tmp_30865-FES%20McFadden%20Curiae841263782.pdf
[2] https://archive.org/download/McFaddenBriefs/tmp_30865-NACDL%20McFadden%20Curiae-17916763.pdf
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