The U.S. Supreme Court agreed to hear a California woman's bid to overturn her conviction for smuggling drugs across the U.S.-Mexican border in a dispute over the scope of prosecution expert witness testimony aimed at undermining, her defense that she acted unwittingly as a "blind" drug mule, Reuters reports. The justices took up Delilah Guadalupe Diaz's appeal after a lower court rejected her bid to exclude the expert witness's testimony that had cast doubt on her claim that she did not know that methamphetamine valued at $368,550 was hidden in the door panels of the car she was driving. A San Diego federal jury found Diaz guilty in 2021 of illegally importing the methamphetamine, a crime that required knowledge that she knew the drugs were in the car.
People who smuggle drugs across borders, sometimes called "mules," may do so for profit but also sometimes do it unwittingly, transporting illegal substances that have been planted on them. These people are called "blind" mules. U.S. District Judge Anthony Battaglia allowed the prosecution's expert witness, a Homeland Security special agent, to 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. Diaz's attorneys contend that the testimony violated the longstanding federal rules governing allowable types of evidence. Border inspectors ordered Diaz, a resident of Moreno Valley, Calif., to roll down a window of the vehicle she was driving and heard a "crunch-like" sound, later finding 56 packages containing 24.5 kilograms of pure methamphetamine. Diaz denied knowledge of the drugs.