Mens Rea and Changing Law
<p>Imagine I buy and sell coffee products, and have done so legally for many years.
However, the FDA decides that coffee is a carcinogen, an addictive drug, and extremely dangerous, and consequently places it on Schedule I drug, along with Heroin.</p>

<p>I continue to buy and sell coffee entirely unaware of the change in law. Then the feds come over, bust down my door and I am facing a charge of dealing schedule 1 drugs, and life imprisonment.</p>

<p>What is the legal situation here? Plainly I had no mens rea, I was entirely unaware of the change in the law, and reasonably would have expected my previously legal activity to continue to be legal.</p>

<p>However, I also know the epithet that ignorance of the law is no defense. So what would my legal situation be here?</p>

<p>In law, there is a distinction between mistake of fact and mistake of law. If the law prohibits X, and you think you're doing Y, that's a mistake of fact. If the law prohibits X, and you know you're doing X, but you think the law prohibits Y, that's a mistake of law. Mistake of fact is generally a defense (although that principle is being eroded), but mistake of law is not. In your hypothetical, you clearly had the intent to sell coffee, so you had mens rea. Mens rea refers to the intent to perform the act that is illegal, not the intent to break the law. If you intend to follow the law, but intentionally perform an act that is against the law, it is the latter that forms mens rea; mens rea refers to your intent regarding the act you are performing, not your intent regarding the law.</p>

<h2>You're going to jail</h2>
<p><a href="https://www.law.cornell.edu/uscode/text/21/841" rel="nofollow noreferrer">21 U.S. Code § 841</a>:</p>
<blockquote>
<p>(a) <strong>Unlawful acts</strong> Except as authorized by this subchapter, it shall be unlawful for any person knowingly or intentionally—</p>
<p>(1) to manufacture, distribute, or dispense, or possess with intent to manufacture, distribute, or dispense, a controlled substance; or</p>
</blockquote>
<p>Do you see where they talk about <em><a href="https://en.wikipedia.org/wiki/Mens_rea" rel="nofollow noreferrer">mens rea</a></em> in there? Its in the word &quot;knowingly&quot;.</p>
<p>Since the adoption of the <a href="http://www.cs.xu.edu/%7Eosborn/main/lawSchool/criminalHtml/bottomScreens/Briefs/Model%20Penal%20Code%20Section%202.02.htm" rel="nofollow noreferrer">model penal code</a> in the 1950s the common law concept of <em>mens rea</em> has been codified. Specifically, knowingly is:</p>
<blockquote>
<p>A person acts knowingly with respect to a material element of an offense when:</p>
<p>(i) if the element involves the nature of his conduct or the attendant circumstances, he is aware that his conduct is of that nature or that such circumstances exist; and</p>
<p>(ii) if the element involves a result of his conduct, he is aware that it is practically certain that his conduct will cause such a result.</p>
</blockquote>
<p>Assuming the law making coffee a prohibited substance has been properly promulgated then your ignorance of it is voluntary ignorance - you could have learned of it and should have learned of it and therefore you &quot;knowingly&quot; chose to distribute coffee in violation of the law.</p>
<p>There is an exception in federal tax law - where the law uses the term &quot;willfully&quot;, SCOTUS has held that this carves out an exception to the traditional rule that ignorance of law cannot be excused.</p>

mens-rea