Opinion ID: 203873
Heading Depth: 3
Heading Rank: 3

Heading: The intersection of overview and expert testimony

Text: Delineating the boundaries of acceptable overview testimony becomes even more complicated when the overview witness is also qualified as an expert. Overview witness testimony is normally limited by the rule that lay opinion testimony is admissible only if it is 1) not grounded in scientific or specialized knowledge but rationally based on the perception of the witness, and 2) helpful to the jury in acquiring a clear understanding of the witness's testimony or the determination of a fact in issue. Fed.R.Evid. 701. In contrast, the Federal Rules permit experts to provide opinions so long as (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case. Fed.R.Evid. 702. Experts, unlike lay witnesses, may base their opinions on facts or data that need not be admissible, as long as these facts are of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject. Fed.R.Evid. 703. Facts or data that are otherwise inadmissible are not to be disclosed to the jury unless the court determines that their probative value in assisting the jury to evaluate the expert's opinion substantially outweighs their prejudicial effect. Id. The Casas court thus appropriately noted that expert witnesses have leeway other witnesses do not, although the government had never sought in Casas to qualify Stoothoff as an expert, and, [m]ore fundamentally, ... Agent Stoothoff's testimony that particular persons were members of the conspiracy was not an appropriate subject for expert testimony. It was not in any way linked to the `specialized knowledge' that Rule 702 requires. Casas, 356 F.3d at 120; see also Johnson, 54 F.3d at 1157 (Rule [703] does not afford the expert unlimited license to testify or present a chart in a manner that simply summarizes the testimony of others without first relating that testimony to some `specialized knowledge' on the expert's part as required under Rule 702 of the Federal Rules of Evidence.). Thus, as with any other witness, courts cannot allow an overview witness to testify as an expert as to matters that are not appropriately the subject of expert testimony. On the other hand, we have often allowed expert testimony regarding the operation of criminal schemes, [i]n particular, expert testimony regarding the description of a typical drug network. García-Morales, 382 F.3d at 18-19 (quotation marks and citation omitted). Therefore, we have held that, while portions of an overview witness's testimony were improperly admitted, other sections of the testimony were acceptable in his capacity as an expert qualified to describe the structure and operation of a typical drug conspiracy. Id. at 17-19. Nevertheless, even appropriate expert testimony under Rule 702 may be excluded under Fed.R.Evid. 403 if its probative value is substantially outweighed by the risk of unfair prejudice it creates. United States v. Lopez-Lopez, 282 F.3d 1, 15 (1st Cir.2002) (quotation marks and citation omitted). While there is no prohibition against a witness testifying as both an expert and a fact witness, courts must be mindful when the same witness provides both lay and expert testimony, United States v. Upton, 512 F.3d 394, 401 (7th Cir.2008), because of the heightened possibility of undue prejudice. The problem is especially acute where the dual roles of expert and fact witness are filled by a law enforcement official, in part because the jury may unduly credit the opinion testimony of an investigating officer based on a perception that the expert was privy to facts about the defendant not presented at trial. Id. at 401. See also United States v. Dukagjini, 326 F.3d 45, 53 (2d Cir.2003) (observing that the use of the case agent as an expert increases the likelihood that inadmissible and prejudicial testimony will be proffered, in part because when the case agent functions as an expert for the government, the government confers upon him the aura of special reliability and trustworthiness surrounding expert testimony, which ought to caution its use) (quotation marks and citation omitted); United States v. Brown, 776 F.2d 397, 401 n. 6 (2d Cir.1985) (observing that the risk of a jury conflating expert and fact testimony is increased when the opinion is given by the very officers who were in charge of the investigation) (quotation marks and citation omitted). The law enforcement/overview witness who testifies as both a fact witness and an expert thus exacerbates the imprimatur problem we have noted earlier.