United States v. Santini

A psychological expert witness cannot form an opinion on data that requires interpretation by an expert in law enforcement record keeping if no interpretation was previously performed.

Brad Ray Santini attempted to cross into the United States from Mexico with 28 kilograms of marijuana in his vehicle. Santini presented the defense that he suffered from cognitive defects and therefore subject to manipulation by others. A government psychological expert testified that Santini had “extensive prior contacts” with law enforcement prior to his injury, arguing his brain injury did not make him more vulnerable to manipulation. The district court held the government’s witness’ testimony admissible. Santini appealed. The Ninth Circuit held the testimony was inadmissible because it failed under FRE 404(b) and FRE 703. The Court found that previous convictions contained in the “rap sheet” relied upon by the expert, were not admitted into evidence, or examined by the Court, and could not support a finding that Santini had “extensive” law enforcement contacts. The Court also found that Santini’s prior convictions for simple possession, indecent exposure, and assault were not “similar behavior.” The Court further held that the testimony failed under FRE 703 because the government’s expert based his opinion on data that required expertise in another field. The government’s expert had found the “rap sheet” hard to understand, did not distinguish among arrests, convictions, or other contacts with law enforcement. The Court also found that the testimony of “extensive” prior contacts with law enforcement was far more prejudicial than probative in assisting the jury with the government witness’ opinion, thus the error in admitting the evidence was harmful in that it was more probable than not that it materially affected the jury’s verdict. VACATED and REMANDED for a new trial.