United States v. Carney
1:20-cr-00121
S.D. OhioApr 19, 2022Background:
- Defendant Furious Suave Carney is charged with distribution of a controlled substance resulting in two deaths; officers recovered a blue piece of paper with white powder (Item 5‑1).
- Hamilton County Crime Lab analyst Mark Squibb found a DNA mixture on Item 5‑1 from at least three contributors; a major profile matched Carney and the minor profile was below reporting thresholds.
- Squibb reported a random-match probability for the major profile of 1 in 299 septillion 400 sextillion and concluded Carney was the source of the major profile.
- Carney moved to exclude the DNA evidence under Rule 702 and requested a Daubert hearing, arguing HCCL’s manual, ‘‘binary’’ interpretation is unreliable for complex (3+ person) mixtures and not validated for such complexity.
- Government defended the methodology as testable, peer‑reviewed in practice, and applied consistent with applicable FBI Quality Assurance Standards (QAS); HCCL had an independent analyst verify Squibb’s interpretation.
- After a Daubert hearing, the court denied Carney’s motion, finding the methodology reliable and challenges go to weight, not admissibility.
Issues:
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Admissibility under Fed. R. Evid. 702 | Methodology reliable and properly applied; helps trier of fact | Manual/binary interpretation of complex mixtures is unreliable and usurps the jury | Admitted; methodology reliable and properly applied; weight for jury |
| Testability of manual, binary interpretation | Method can be tested; independent second analyst verified results; validation studies exist | Subjective visual calls and lack of contemporaneous notes make it untestable | Testable; lack of notes does not defeat reliability |
| Peer review / general acceptance | Method used by many labs; HCCL accredited and methodologies reviewed in practice | Manual method is outdated and not sufficiently peer‑reviewed for complex mixtures | Sufficiently peer‑reviewed and generally accepted; not dispositive of admissibility |
| QAS compliance, validation for complex mixtures & error rate | HCCL complied with applicable QAS based on instrument installation date; standards mitigate risk | HCCL did not validate for complex mixtures per 2020 QAS; error rate not shown | HCCL compliant with applicable QAS; validation/ error‑rate concerns go to weight, not exclusion |
Key Cases Cited
- Daubert v. Merrell Dow Pharms., 509 U.S. 579 (1993) (district court gatekeeping role and reliability factors for expert testimony)
- United States v. Gissantaner, 990 F.3d 457 (6th Cir. 2021) (applying Daubert factors in forensic-DNA context)
- United States v. Bonds, 12 F.3d 540 (6th Cir. 1993) (distinguishing admissibility vs. adequacy of testing/results)
- Conwood Co. v. U.S. Tobacco Co., 290 F.3d 768 (6th Cir. 2002) (district courts’ leeway in assessing reliability)
- Mitchell v. Gencorp Inc., 165 F.3d 778 (10th Cir. 1999) (peer review via other scientists' evaluation may suffice)
- United States v. Williams, 382 F. Supp. 3d 928 (N.D. Cal. 2019) (excluding DNA evidence where analyst input of contributor number was critical and validation lacking)