The Supreme Court recently gave prosecutors a green light to prove defendants’ criminal intent vicariously, by offering expert testimony about the mental state of people “like” the defendant.
At the tail end of its recent term, the court held in Diaz v. United States that while Rule 704(b) of the Federal Rules of Evidence prohibits an expert from testifying that a particular defendant had a culpable state of mind when engaged in allegedly criminal conduct, that rule does not bar an expert from testifying that “most people” have a guilty mental state when they engage in the same activity.
