United States v. Foust, 989 F.3d 842

Justin Foust, owner of Platinum Express, was convicted of six counts of wire fraud, aggravated identity theft, and money laundering for submitting fraudulent invoices to Chesapeake Energy totaling over $4.5 million; sentenced to 121 months’ imprisonment.
Foust admitted the invoices were improper and the services not performed, but denied forging Chesapeake employees’ signatures/IDs.
The government presented handwriting expert Arthur Linville, a board‑certified forensic document examiner, who testified that signatures attributed to Chesapeake employee Bobby Gene Putman were freehand forgeries and matched Foust’s handwriting based on comparisons to exemplars from 2002, 2011, and 2017.
The district court held a Daubert hearing, found Linville’s methodology acceptable under Rule 702, and admitted his testimony; the jury convicted on counts associated with Putman’s invoices (but hung on counts involving cut‑and‑paste forgeries tied to another employee).
On appeal Foust argued the expert’s methodology was unreliable under Daubert/Kumho and that Linville used unreliable data because his exemplars were not sufficiently contemporaneous; the Tenth Circuit affirmed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admissibility of handwriting‑comparison methodology under Rule 702/Daubert	Govt: Linville is qualified; handwriting comparison is an accepted, experience‑based methodology and was reliably applied	Foust: Methodology unreliable under Daubert/Kumho; Daubert factors (peer review, error rates, standards) not satisfied	Court: District court did not abuse discretion; Daubert factors were mixed but supported admissibility for experience‑based handwriting analysis; deference to district court’s judgment
Reliability of underlying data (contemporaneous exemplars)	Govt: Exemplars were sufficiently comparable; timing issues go to weight, not admissibility	Foust: Linville used exemplars outside his stated 1–2 year contemporaneous preference, undermining the analysis	Court: No strict two‑year rule; Linville explained variability; exemplar timing affects weight for jury, not exclusion; admission affirmed

Daubert v. Merrell Dow Pharms., 509 U.S. 579 (1993) (factors for assessing expert testimony admissibility)
Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999) (Daubert standard applies flexibly to experience‑based experts)
Etherton v. Owners Ins. Co., 829 F.3d 1209 (10th Cir. 2016) (abuse‑of‑discretion standard for Daubert review)
United States v. Nacchio, 555 F.3d 1234 (10th Cir. 2009) (Rule 702 steps: qualifications and reliability of methodology)
United States v. Baines, 573 F.3d 979 (10th Cir. 2009) (evaluating Daubert factors for forensic, experience‑based evidence)
United States v. Crisp, 324 F.3d 261 (4th Cir. 2003) (recognition of longstanding use of handwriting analysis)
In re Urethane Antitrust Litig., 768 F.3d 1245 (10th Cir. 2014) (challenges to expert data generally go to weight, not admissibility)