Supreme Court Just Made It Easier to Be Convicted: Noah Feldman

Can the prosecution call a cop as an expert witness to testify in a drug-trafficking case that most drug couriers — not necessarily the one on trial — know they are carrying drugs? The Supreme Court has said yes, despite a clear federal rule that says an expert can’t testify as to the defendant’s state of mind. The decision is wrong, because it invites the jury to conflate abstract statistical probabilities with the specific circumstances of the individual case.

Delilah Diaz, a US citizen, was stopped in the car she was driving across the border into the US from Mexico. The ...