and to provide the opponent with a fair opportunity to test the merit of the expert’s testimony through focused cross-examination.” Fed.R.Crim.Proc. 16(a)(1)(E) (advisory committee’s note). In sum, rather than testimony “based on the perceptions of the witness”-as the district court described it when overruling Lopez’s objeetions-the bulk of the above opinion testimony is properly characterized as testimony based on the perceptions, education, training, and experience of the witness. It requires precisely the type of “specialized knowledge” of law enforcement governed by Rule 702. Trial courts must ensure that experts are qualified to render their opinions and that the opinions will assist the trier of fact. This careful analysis was absent in this case. See also Webb, 115 F.3d at 714 (<HOLDING>). As judges who have heard such testimony many
recognizing that the expert was particularly qualified to give his opinion holding that the plaintiffs experts were not qualified to offer a medical opinion as to the cause of death because they are not physicians nor otherwise properly qualified to offer a medical opinion holding that rules of evidence do not permit an expert to give opinion or state legal conclusions regarding a question of law holding that because the tendered expert witness was a licensed psychologist and not a medical doctor he was not qualified to state an expert medical opinion regarding the cause of johns injury holding that an expert opinion on a question of law is inadmissible