The testimony of a scientific expert witness may be instrumental in tipping a judgment in favour of its proponent but it can nevertheless be excluded if it has the tendency to delude rather than making clear the issue at hand. Moreover, recently the Fourth Circuit, in the matter of U.S.A. v. Ryan Christopher Fultz (2015 U.S. App. LEXIS 1730), added an extra burden on the shoulders of the party proposing to adduce expert evidence by imposing on it the onus of proving its reliability.
If being a convicted felon was already not good enough, Ryan Christopher Fultz, by committing a bevy of iniquitous acts gave additional reasons to the law enforcing agencies to be displeased with him. He was convicted on charges of possessing firearm, in violation of 18 U.S.C. § 922(g)(1) (2012); possessing the same with the intention of distributing a mixture and substance containing a detectable amount of cocaine base, in violation of 21 U.S.C. § 841(a)(1) (2012); possessing, brandishing, and discharging a firearm in furtherance of a drug trafficking crime, in violation of 18 U.S.C. § 924(c)(1) (2012); and aiding and abetting the latter two offenses, 18 U.S.C. § 2 (2012).
An expert witness proffered to testify in favor of Fultz before the United States District Court for the Eastern District of Virginia. He proposed to state under oath that it would be unfeasible to consider Fultz as the shooter of the AR-15 Bushmaster especially keeping in mind the spot in the crime scene where the .223 caliber shell casings were found. At trial, the district court excluded a portion of the testimony of Fultz’s expert witness. Fultz preferred an appeal before the United States Court of Appeals for the Fourth Circuit. Fultz claimed that the district court was guilty of two transgressions. Firstly, it abused its discretion by excluding the expert testimony and secondly, it failed to grant a new trial to Fultz on the ground that the testimony was wrongfully excluded.
In exercising its power of review, the Fourth Circuit referred to Federal Rule of Evidence 702 – a benchmark for district courts when determining the admissibility of an expert opinion [United States v. Wilson, 484 F.3d 267, 274 (4th Cir. 2007)] under which the district court acts as a concierge “ensuring that an expert’s testimony both rests on a reliable foundation and is relevant” to the fact at issue [Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 597 (1993)].
Reliability of the expert’s opinion was the primary issue before the trial and the Appellate court. The Fourth Circuit appreciated the importance of carefully scrutinizing the reliability of the expert’s testimony primarily because of its ability of being powerful and misleading, at the same time. In Daubert, the Supreme Court had enlisted five factors that could act as a ready reckoner for district courts when evaluating the reliability of scientific expert testimony. But the Appellate court observed that the list was neither “definitive nor exhaustive” [United States v. Crisp, 324 F.3d 261, 266 (4th Cir. 2003)] since in the end, the burden of proving the reliability of the testimony would be borne by the one who would advocate it [Cooper v. Smith & Nephew, Inc., 259 F.3d 194, 199 (4th Cir. 2001)].
The Fourth Circuit concluded that Fultz had failed to prove the reliability of his expert’s opinion on two counts.
Firstly, Fultz could not espouse the validity of his expert witness’s methodology- that the shooter’s position could be gauged by merely examining the location of the shell casings. Fultz had provided additional support for his expert’s method in his motion for a new trial, but he had failed to do so at or before trial and there was nothing which could prevent him from so doing bearing in mind the fact that the Daubert factors were well-established.
Secondly, even if the expert witness’s methodology was accepted in the relevant scientific community, the crime scene in the case had been disturbed to such a great extent that any estimation of the shooter’s position based on the physical evidence would be pure guesswork.
On appeal, the Fourth Circuit affirmed the decision of the district court of excluding the expert’s testimony because it had “a greater potential to mislead than to enlighten” (Westberry, 178 F.3d at 261)