06/27/2024 - Federal Rules of Evidence and General Mental State and Exact Mental State in Spotlight

Washington: On Thursday, The U.S. Supreme Court ruled against Delilah Guadalupe Diaz from California convicted of smuggling drugs across the U.S.-Mexican border who challenged prosecution expert testimony that she was a ‘blind drug mule,’ without knowledge of the illegal cargo she carried.

She claimed the car belonged to her boyfriend and was unaware of his identity, address or whereabouts. The car also had a GPS tracking device and a phone which she could not unlock. The case highlighted if expert witnesses could opine about the general mental state of defendants and whether they knew if they were committing a crime.

The justices, in a 6-3 ruling, upheld a lower court's decision to allow testimony by an expert witness who called into question the defendant’s contention that she did not know that methamphetamine priced at $368,550 was concealed under the windows of the car she was driving.

A judge in this case permitted an expert witness to testify in the trial that drivers usually know they are being hired to traffic drugs.
A jury in federal court in San Diego found Diaz guilty in 2021 of illegally importing the methamphetamine, a crime that required proving that she knew the drugs were in the car. Diaz was sentenced to seven years in prison.

The defendant’s lawyers argued that the testimony violated a provision of the longstanding Federal Rules of Evidence governing the types of evidence allowable in legal cases. The rule bars expert witnesses from opining on the "mental state" of defendants related to an alleged offense and whether they knew they were committing a crime.

"Because the expert witness did not state an opinion about whether (Diaz) herself had a particular mental state, we conclude that the testimony did not violate" the evidence rule, Justice Clarence Thomas wrote in the majority opinion, joined by four fellow conservative justices and liberal Justice Ketanji Brown Jackson.

In a dissent, conservative Justice Neil Gorsuch, joined by liberal Justices Sonia Sotomayor and Elena Kagan, said that the outcome gives prosecutors a powerful new tool.
"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," Gorsuch wrote.
Gorsuch added: "What authority exists for allowing that kind of charade in federal criminal trials is anybody's guess."

U.S. District Judge Anthony Battaglia during the trial let the prosecution's expert witness, a Homeland Security special agent, testify that "in most circumstances, the driver knows they are hired." The expert also told the jury that drug-trafficking organizations generally do not entrust large quantities of drugs to unknowing couriers.

People who smuggle drugs across borders, sometimes called "mules," may do so for profit but also sometimes do it unwittingly, transporting illegal substances that were planted on them. These individuals are often called "blind" mules.

In 2020, border inspectors ordered Diaz, a resident of Moreno Valley, California, to roll down a window of the Ford Focus vehicle she was driving and heard a "crunch-like" sound, later finding 56 packages containing more than 24 kilograms of pure methamphetamine. Diaz denied any knowledge of the drugs.