Expert Witnesses

The First Circuit vacated a defendant’s conviction for attempted coercion and enticement of a minor. The Court held that the trial court erred in excluding certain expert testimony from a clinical psychologist. While the trial court had allowed the witness to testify as an expert in the field of internet sexual behaviors, it erred in prohibiting the witness from opining on the defendant’s internet chats and whether chats like his met the pattern shown by child predators who communicate with minors online.

The Ninth Circuit vacated a defendant’s conviction for transporting marijuana and remanded for a new trial because the district court did not properly assess the reliability of the government’s expert witness, an ICE agent, who testified that the cartel does not employ unwilling couriers. The Court held that this was harmful error because it directly undercut the defendant’s credibility and duress defense.

The Eleventh Circuit affirmed the defendant’s conviction for healthcare fraud, holding that there was sufficient evidence based on testimony regarding “red flags” at the defendant’s pharmacy, including patients from out of state, unrealistically high prices, and discrepancies in billing and inventory. The Court also rejected the defendant’s challenges to lay witness testimony from patients stating they received medication that they did not need and held that the Government replacing its expert did not prejudice the defendant where the substance of the testimony stayed the same.

Evidence/Expert Testimony – Expert testimony discussing a theory that lacks sufficient testing, known or potential error rates, control standards, acceptance among the science community, and a connection between the theory and the underlying research is sufficiently unreliable to be excluded. Further, a peer-reviewed paper mentioning the theory is insufficient alone to prove reliability. Evidence/Rebuttal – […]

The Court affirmed the defendant’s convictions for enticing a minor under § 2422(b) but reversed his conviction under § 373 for solicitation to commit a crime of violence, holding that kidnapping under § 1201(a) is not a “crime of violence” under the categorical approach applicable to § 373. The Court also held that the defendant’s right to a complete defense was not violated by the trial court’s proper rulings on the inadmissibility of the defense experts’ testimony.