United States v. Hunt, 464 F.Supp.3d 1252

Defendant Dominic Hunt was charged in a third superseding indictment with, inter alia, two counts of being a felon in possession of ammunition based on cartridge casings recovered at two separate January–February 2019 shooting scenes.
OCPD examiner Ronald Jones and ATF examiner Howard Kong concluded the four recovered 9mm casings were likely fired from the same unknown firearm, possibly a Smith & Wesson 9mm; the Government intends them as trial experts to explain methods and findings.
Hunt moved in limine to exclude the firearm/toolmark identification testimony or, alternatively, for a Daubert hearing, challenging the reliability of the AFTE methodology and the experts’ application of it; Hunt did not contest relevance or qualifications.
The Government defended the AFTE method as tested, peer-reviewed, having low error-rate studies, and generally accepted; it produced the examiners’ reports and documentation of peer review and training.
The Court applied Rule 702 and Daubert factors, concluded the AFTE-based testimony is admissible (subject to specified limitations), denied Hunt’s motion to exclude and denied the request for a Daubert hearing.
The Court ordered trial limitations consistent with DOJ guidance: experts may not claim infallibility, exclude all other sources, provide unsupported numerical probabilities, or use ‘‘reasonable scientific certainty’’ except in the approved field-specific phrasing.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admissibility of firearm toolmark methodology under Daubert	AFTE method is tested, peer-reviewed, has low error rates in studies, and is generally accepted	Method is insufficiently tested, subjective, lacks black-box studies and known error rate	Admissible. Most Daubert factors favor admissibility; only subjectivity factor weighs against but is not dispositive
Whether experts reliably applied methods under Rule 702(d)	Examiners produced detailed reports, underwent peer review, have training and proficiency records	Reports lack sufficient documentation, no independent verification, did not meet PCAST-prescribed validity checks	Application reliable. Court finds reports and peer review adequate; PCAST requirements not mandatory under Rule 702(d)
Need for a formal Daubert hearing	Briefing suffices to perform gatekeeping role	Requests a full hearing to test reliability before testimony	No hearing required. Court satisfied by briefs and record; gatekeeping performed on motion in limine
Scope limits on expert testimony at trial	Experts will follow DOJ guidance and avoid absolute certainty or sole-source assertions	Seeks tighter limits to prevent jury confusion and overstatement	Court imposes limits: no claim of exclusion of all other sources, no infallibility, no unsupported numeric probabilities, restrict language to reasonable degree of ballistic certainty or similar phrasing

Daubert v. Merrell Dow Pharm., 509 U.S. 579 (1993) (establishes federal gatekeeping factors for expert evidence)
Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999) (Daubert gatekeeping applies to all expert testimony)
Bitler v. A.O. Smith Corp., 400 F.3d 1227 (10th Cir. 2005) (district court gatekeeper role explained)
Avitia-Guillen, 680 F.3d 1253 (10th Cir. 2012) (Rule 702 relevance and reliability framework)
Nacchio, 555 F.3d 1234 (10th Cir. 2009) (proponent bears burden to show admissibility)
United States v. Monteiro, 407 F. Supp. 2d 351 (D. Mass. 2006) (discussion of longstanding judicial treatment of firearm identification testimony)
United States v. Romero-Lobato, 379 F. Supp. 3d 1111 (D. Nev. 2019) (collects authorities finding AFTE method tested and admissible)
United States v. Ashburn, 88 F. Supp. 3d 239 (E.D.N.Y. 2015) (addresses error rate, subjectivity, and testimony limitations)