Justice Neil Gorsuch chastised the Supreme Court majority for ruling against a drug trafficking defendant on Thursday, arguing the decision gives the government too much prosecutorial power.
Delilah Guadalupe Diaz appealed to the justices after a jury found her guilty of importing methamphetamine across the southern border, which requires the government to prove that Diaz was knowingly transporting drugs.
Diaz, who asserts she was a blind mule and was unaware of the drugs in her car, contended that federal evidence rules did not permit prosecutors to have their expert witness testify to the jurors that most couriers know they are carrying illegal drugs.
In a 6-3 decision, the Supreme Court on Thursday rejected Diaz’s appeal. Justice Clarence Thomas’s majority opinion was joined by liberal Justice Ketanji Brown Jackson and four other conservatives: Chief Justice John Roberts, Justice Samuel Alito, Justice Brett Kavanaugh and Justice Amy Coney Barrett.
Gorsuch, former President Trump’s first appointee to the court who at times has broken with his fellow conservatives to rule for criminal defendants, did so again on Thursday, saying the expert testimony was inadmissible.
“The upshot? The government comes away with a powerful new tool in its pocket,” Gorsuch wrote, joined by liberal Justices Sonia Sotomayor and Elena Kagan.
“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 continued. “Then, the government need do no more than urge the jury to find that the defendant is like ‘most’ people and convict.”
The case revolved around a federal evidence rule prescribing that 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.”
Thomas found the rule didn’t prohibit the testimony Diaz’s expert, a special agent in the Department of Homeland Security, because they did not express an opinion about Diaz herself, only drug traffickers generally.
“An expert’s conclusion that ‘most people’ in a group have a particular mental state is not an opinion about ‘the defendant,’” Thomas wrote.
Gorsuch lamented in his dissent, “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.”
