Supreme Court Broadens Use Of Expert Testimony Against Accused Criminals

Authored by Zachary Stieber via The Epoch Times (emphasis ours),

The U.S. Supreme Court on June 20 sided with the government in a case centering on expert testimony in criminal trials.

Supreme Court Associate Justice Clarence Thomas poses for an official portrait at the East Conference Room of the Supreme Court building in Washington on Oct. 7, 2022. (Alex Wong/Getty Images)

In a 6–3 ruling, the justices said that experts can testify to how “most people” in a group to which a defendant belongs think, upholding a lower court ruling.

The case was brought by Delilah Diaz, a U.S. citizen who was stopped at the U.S.-Mexico border. Officers found nearly 28 kilograms of drugs hidden in the door panels of the car she was driving, and she was charged with violating a law that requires showing a defendant “knowingly” transported drugs.

Ms. Diaz said her boyfriend used her by luring her to Mexico, then loaning her a car to return to the United States that was, unbeknownst to her, filled with drugs.

The government called Andrew Flood, a special agent, to testify that drug traffickers typically don’t give large quantities of drugs to people unless the people know they are transporting the drugs.

“Generally, it’s a risk of your—your cargo not making it to the new market; not knowing where it’s going; not being able to retrieve it at the ending point, at your point B. So there’s a risk of not delivering your product and, therefore, you’re not going to make any money,” he testified.

Mr. Flood also said that there were cases where drug traffickers placed drugs in vehicles without the drivers knowing, but that none of those known “schemes” matched the circumstances of Ms. Diaz.

Challenging Testimony

Ms. Diaz brought up a federal rule known as Rule 704(b) that states expert witnesses “must not state an opinion about whether the defendant did or did not have a mental state or condition that constitutes an element of the crime charged or of a defense.” But a district judge ruled that Mr. Flood could tell jurors about whether couriers generally knew they were transporting drugs. At trial, he testified to that effect. The jury found Ms. Diaz guilty.

Ms. Diaz appealed, but a federal appeals court also rejected her arguments against the testimony.

Lawyers for Ms. Diaz had written in a filing to the Supreme Court that the plain text of the rule “forecloses limiting its reach to an ‘explicit opinion’ regarding the defendant’s knowledge.” Generalizing about most drug carriers was an improper workaround of the rule, they said.

“This is true of many generalizations about a class of individuals,” they wrote. “Say a patient asks his therapist whether he is depressed and she responds, ‘People do not usually have trouble getting out of bed in the morning unless they are depressed.’ She has clearly expressed an ‘opinion about’ her patient’s mental state. Likewise for a high-school teacher who, when asked whether one of her students knew that he was not supposed to get outside help on a take-home exam, responds, ‘High-school seniors generally know the honor code.’”

In the Supreme Court ruling siding against Ms. Diaz, Justice Clarence Thomas wrote that “because the expert witness did not state an opinion about whether petitioner herself had a particular mental state, we conclude that the testimony did not violate Rule 704(b).”

“Agent Flood instead testified about the knowledge of most drug couriers,” he added later. “Specifically, he explained that ‘in most circumstances, the driver knows they are hired … to take the drugs from point A to point B.’ That opinion does not necessarily describe Diaz’s mental state. After all, Diaz may or may not be like most drug couriers.”

Defense Arguments

Defense lawyers, during cross-examination of the agent, also established that Mr. Flood was not involved in Ms. Diaz’s case and that there had been cases before involving people carrying drugs without their knowledge.

“The jury was thus well aware that unknowing couriers exist and that there was evidence to suggest Diaz could be one of them. It simply concluded that the evidence as a whole pointed to a different conclusion: that Diaz knowingly transported the drugs. The jury alone drew that conclusion,” Justice Thomas said.

Justice Thomas was joined by Justices John Roberts, Samuel Alito, Brett Kavanaugh, Amy Coney Barrett, and Ketanji Brown Jackson.

Justice Neil Gorsuch said in a dissent that the majority was “carv[ing] a new path” around the federal rule.

The ruling means “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,” he wrote. “Then, the government need do no more than urge the jury to find that the defendant is like ’most’ people and convict. What authority exists for allowing that kind of charade in federal criminal trials is anybody’s guess, but certainly it cannot be found in Rule 704.”

Justice Gorsuch was joined his dissent by Justices Sonia Sotomayor and Elena Kagan.