The U.S. Supreme Court issued a split opinion Thursday in a case originating out of San Diego, ruling that expert witnesses can continue to tell jurors that most drug couriers caught at the U.S.-Mexico border know they’re transporting drugs, even when the defendants argue they were unwitting “blind mules.”
The case, Delilah Guadalupe Diaz v. United States of America, centered around a specific rule of evidence in federal law dealing with a defendant’s mental state and knowledge of a crime, and the opinions of experts testifying about a defendant’s criminal intent.
In essence, the court ruled that an expert can testify about the criminal intent or mental state of most defendants charged with a particular crime, and that such testimony is not too general — the jury can still decide if a specific defendant is like most other defendants or not.
The ruling has major implications for the San Diego region, where federal prosecutors charge hundreds of people each year with illegally importing drugs across the border. The most common defense for such charges is the blind mule argument, in which defendants assert they were unaware that smugglers hid drugs in their vehicles. But the ruling could also have wider implications for defendants in other kinds of cases when there are questions of criminal intent.
Local defense attorneys said Thursday the ruling is likely to turn trials into a “battle of experts” offering contradicting opinions about a defendant’s mental state — the very problem Congress sought to fix when it created the rule.
Justice Clarence Thomas authored the 6-3 majority opinion, which affirmed a previous ruling by the 9th U.S. Circuit Court of Appeals. The appeals court had ruled that Homeland Security Investigations Special Agent Andrew Flood had not violated the federal evidence rule — 704(b) — when he testified at Diaz’s trial that “in most circumstances, the driver knows they are hired … to take the drugs from point A to point B.”
Thomas wrote that Flood did not violate the rule because he did not testify specifically that Diaz knew she was transporting drugs or that all couriers know they’re transporting drugs.
“Agent Flood asserted that Diaz was part of a group of persons that may or may not have a particular mental state,” Thomas wrote. “Of all drug couriers — a group that includes Diaz — he opined that the majority knowingly transport drugs. The jury was then left to decide: Is Diaz like the majority of couriers? Or, is Diaz one of the less-numerous-but-still-existent couriers who unwittingly transport drugs? The ultimate issue of Diaz’s mental state was left to the jury’s judgment.”
‘Party agnostic’
San Diego defense attorney Danielle Iredale, who first represented Diaz and raised the issue at trial, predicted in March after the Supreme Court heard oral arguments that the decision would involve “strange bedfellows” and be close. “I don’t think the split is necessarily going to be along the typical ideological lines,” Iredale predicted after attending the oral arguments in person.
She was right.
Justice Ketanji Brown Jackson, a nominee of President Joe Biden, wrote a concurrence to Thomas’ opinion, ing the majority along with Republican-appointed justices Thomas, John Roberts, Samuel Alito, Brett Kavanaugh and Amy Coney Barrett. Justice Neil Gorsuch, a nominee of President Donald Trump, wrote the dissent, ed by justices Sonia Sotomayor and Elena Kagan, both appointees of President Barack Obama.
Jackson wrote in her concurrence that the rule in question “is party agnostic,” a point that she had focused on during oral arguments.
“Indeed, the type of mental-state evidence that Rule 704(b) permits can prove essential not only for prosecutors, but for defendants as well,” Jackson wrote.
Iredale, who runs a solo private criminal defense practice, said she was initially crestfallen Thursday after reading the decision. But she quickly turned her focus to the positives.
“Now that (the government) can call experts to testify about an entire class of people, we can do the same on the other side,” Iredale said. She said defense attorneys have typically been trepidatious in the past about opening such a door.
Tommy Vu, also a private defense attorney, held a similar view. “It is now imperative for the defense to counter with their own expert to testify about the prevalence of unknowing drug couriers (or) blind mules,” Vu told the Union-Tribune. Vu said the fear among defense attorneys is that while a defense expert can testify that only some drug couriers are blind mules, a government expert can testify that most drug couriers know what they’re doing, and jurors will side with “most” over “some.”
But Vu said Thursday’s ruling won’t affect the prevalence of blind mule defenses. “Irrespective of the Supreme Court’s ruling, this defense is rooted in truth and reality as some of our clients are in fact unknowing couriers,” he said.
The government has acknowledged that Mexican drug-smuggling groups sometimes use the vehicles of unwitting victims — such as students or workers who cross the border at routine and predictable times — but maintains that such cases are rare. San Diego defense attorneys contend the use of blind mules is more common than the government will it and beneficial to smugglers who can track the drug load with a hidden GPS, don’t have to pay the driver and need not worry about the driver snitching, stealing the drugs or acting nervous during inspections.
Federal authorities arrested Diaz, a U.S. citizen and Moreno Valley resident, in August 2020 at the San Ysidro Port of Entry after finding some 60 pounds of methamphetamine concealed within the doors of her vehicle. She maintained from the beginning that the car belonged to her boyfriend and she didn’t know about the drugs.
Before trial, Iredale unsuccessfully attempted to block the testimony of Flood, the federal agent, that drug-trafficking organizations typically don’t use blind mules because it’s too risky. The jury convicted Diaz, who then appealed to the 9th Circuit, again unsuccessfully.
The petition asking the Supreme Court to take up the case, filed by Stanford law professor Jeffrey L. Fisher, the co-director of Stanford’s Supreme Court Litigation Clinic, cited previous reporting from the Union-Tribune. It argued that the 9th Circuit’s interpretation of the evidence rule “lightens the Government’s burden to prove knowledge beyond a reasonable doubt” by allowing sweeping generalizations about a particular class of defendants rather than evidence specific to the actual defendant.
The rule at the heart of the case states in part that “an expert witness must not state an opinion” about a defendant’s state of mind. Congress amended the rule to its current form through the Insanity Defense Reform Act of 1984 in response to the acquittal of President Ronald Reagan’s would-be assassin, John Hinckley Jr. A jury found Hinckley not guilty by reason of insanity after hearing conflicting testimony about whether he met the legal standard for insanity.
In blind mule cases, the issue becomes not whether the driver is insane, but whether the driver knows he or she is committing a crime.
Iredale said Thursday’s ruling could affect other types of cases in which criminal intent is in question, such as charges involving possession of drugs with intent to distribute. Government and defense experts can offer contrasting opinions about what “most” people who possess a certain amount of drugs plan to do with those drugs.
Vu predicted prosecutors will rely heavily on the ruling. “Going forward, we expect the government to always present such expert testimony across the board.”
The U.S. Attorney’s Office for the Southern District of California declined to comment on Thursday’s ruling.
‘An expert in mindreading’
Gorsuch was scathing in his dissent, arguing that the “upshot” of the court’s majority opinion is that “the government comes away with a powerful new tool in its pocket.”
Wrote Gorsuch: “Prosecutors can now put an expert on the stand — someone who apparently has the convenient ability to read minds — and let him hold forth on what ‘most’ people like the defendant think when they commit a legally proscribed act. Then, the government need do no more than urge the jury to find that the defendant is like ‘most’ people and convict.”
Gorsuch went on to argue that in Diaz’s case, prosecutors could have pointed to plenty of circumstantial evidence that would allow the jury to infer that she knew about the drugs and was not a blind mule.
“The government was free to argue to a jury, asking it to conclude that Ms. Diaz’s story was ‘transparently flimsy,’” Gorsuch wrote. “Day in and day out, the government secures convictions for the knowing importation of drugs in just this way … There was no need to gild the lily by calling to the stand an ‘expert’ in mindreading. And there is certainly no cause for this Court to sanction the practice.”
Gorsuch went on to write that “the problem of junk science in the courtroom is real and well documented … And perhaps no ‘science’ is more junky than mental telepathy.”
Jackson wrote in her concurrence with Thomas that she “fully (acknowledges) that there are serious and well-known risks of overreliance on expert testimony — risks that are especially acute in criminal trials.” But she wrote that there are other safeguards outside of Rule 704(b) to prevent misuse of expert testimony.
Jackson wrote that district court judges also have a role to play by providing clear and specific instructions to jurors when they hear testimony about a defendant’s mental state or criminal intent.
Diaz, the defendant in the case, remains in federal prison in Arizona. She’s expected to be released early next year.
