Supreme Court Tests Bounds of Expert Testimony in Criminal Cases
Published on March 20, 2024
The Supreme Court pressed attorneys on March 19 to specify how much expert witnesses can comment on the knowledge of particular groups of people in criminal wrongdoing. Oral argument in Diaz v. United States focused on the legal principle of mens rea, or the idea that a criminal defendant understood they were breaking the law or engaging in wrongdoing while committing a crime. Delilah Diaz was convicted for importation of methamphetamine despite claiming she didn’t know nearly 28 kilograms were hidden in her boyfriend’s car, which she was driving across the Mexican border in 2020. Homeland Security agent Andrew Flood had testified that in most cases, drivers who are carrying drugs know they have been hired for that purpose....