The Government must prove that a doctor knowingly and intentionally prescribed drugs in an unauthorized manner in order to convict under the Controlled Substances Act, the U.S. Supreme Court held June 27 in Ruan v. United States.
Section 841 of the CSA makes it illegal “except as authorized…for any person knowingly or intentionally” to dispense a controlled substance.
A prescription is authorized only when a doctor issues it “for a legitimate medical purpose.”
Xiulu Ruan, a licensed medical doctor, was convicted of prescribing opioids not “as authorized.” 
Jurors were allowed to convict based on finding that his prescriptions fell outside an objective standard of medical practice. 
He was sentenced to more than 20 years in prison.
The Eleventh Circuit affirmed, ruling that the doctor’s conduct “must be evaluated based on an objective standard, not a subjective standard.”
The Supreme Court reversed, in a 6-3 opinion.
The question is whether it is “sufficient for the Government to prove that a prescription was in fact not authorized, or must the Government prove that the doctor knew or intended that the prescription was unauthorized,” the Court said.
“We hold that the statute’s ‘knowingly or intentionally’ mens rea applies to authorization,” the Court said.  “After a defendant produces evidence that he or she was authorized to dispense controlled substances, the Government must prove beyond a reasonable doubt that the defendant knew that he or she was acting in an unauthorized manner, or intended to do so.”
“First, as a general matter, our criminal law seeks to punish the ‘vicious will,’” the Court said.  “With few exceptions, wrongdoing must be conscious to be criminal.”
“Consequently, when we interpret criminal statutes, we normally start from the longstanding presumption … that Congress intends to require a defendant to possess a culpable mental state,” the Court said.
In applying a scienter provision, prior cases have “held that a word such as ‘knowingly’ modifies not only the words directly following it, but also those other statutory terms that ‘separate wrongful from innocent acts,’” the Court said.
Furthermore, the “severe penalties” for violating Sec. 841 – including up to life in prison — “counsel in favor of a strong scienter requirement,” the Court said.  “Section 841 does not define a regulatory or public welfare offense that carries only minor penalties,” thus falling “outside the scope of ordinary scienter requirements.”
“[T]he statutory clause in question plays a critical role in separating a defendant’s wrongful from innocent conduct,” the Court said.
The Government’s objective standard “would turn a defendant’s criminal liability on the mental state of a hypothetical ‘reasonable’ doctor, not on the mental state of the defendant himself,” the Court said.  “We have rejected analogous suggestions in other criminal contexts.”
“In a Sec. 841 prosecution, then, once the defendant satisfies the initial burden of production by producing evidence of authorization, the burden of proving lack of authorization shifts back to the Government,” the Court said.
“[T]he Government must prove lack of authorization beyond a reasonable doubt,” the Court said.
The Court concluded by noting that an objective medical standard of care is not entirely irrelevant, because it can be used to show knowledge of lack of authorization through circumstantial evidence.
The more unreasonable a defendant’s asserted subjective beliefs are, when measured against objective criteria, the more likely the jury will find the Government has carried its burden of proving knowledge, the Court said.
“But the Government must still carry this burden,” the Court concluded.  “And for purposes of a criminal conviction under Sec. 841, this requires proving that a defendant knew or intended that his or her conduct was unauthorized.”
Justice Alito, joined by Justices Thomas and Barrett, agreed the conviction should be reversed, but on different grounds.
In a concurring opinion, they said the Court was confusing the elements of an offense with an affirmative defense, and creating a “new hybrid” with elements of both.
“The consequences of this innovation are hard to foresee, but the result may well be confusion and disruption,” they said.