United States v. Kavon Jackasal

Court of Appeals for the Eleventh Circuit·Decided September 2, 2025·No. 24-11011·Unpublished

Opinion

NOT FOR PUBLICATION

In the

United States Court of Appeals For the Eleventh Circuit

No. 24-11011

Non-Argument Calendar

UNITED STATES OF AMERICA, Plaintiff-Appellee,

versus

KAVON JACKASAL, Defendant-Appellant.

Appeal from the United States District Court for the Middle District of Florida D.C. Docket No. 8:22-cr-00233-KKM-TGW-1

Before JILL PRYOR, NEWSOM, and BRASHER, Circuit Judges. PER CURIAM:

Kavon Jackasal appeals his conviction for distributing the fentanyl that caused Valerie Mouw’s death. He argues that the district court abused its Daubert discretion by admitting a Drug

2 Opinion of the Court 24-11011

Enforcement Administration chemist as an expert witness—according to Jackasal, the chemist’s methodology wasn’t sufficiently reliable. And he argues that there wasn’t enough evidence for a reasonable jury to find that the fentanyl he distributed to Mouw resulted in her death. We disagree and affirm.

I

“[I]t is difficult to persuade a court of appeals to reverse a district court’s judgment on Daubert grounds.” United States v. Brown, 415 F.3d 1257, 1264 (11th Cir. 2005). After all, we review a district court’s decisions about the admissibility and reliability of expert opinion for abuse of discretion. United States v. Barton, 909 F.3d 1323, 1330 (11th Cir. 2018). We are especially sensitive to district courts’ discretion with respect to “Daubert issues in particular, an area where the abuse of discretion standard thrives.” Brown, 415 F.3d at 1266. Of course, “granting considerable leeway is not the same thing as abdicating appellate responsibility.” Id. In the Daubert context, we may still conclude that a district court has abused its discretion if it “applies the wrong law, follows the wrong procedure , bases its decision on clearly erroneous facts, [] commits a clear error in judgment,” or “essentially abdicat[es] its gatekeeping role.” Id.

This appeal is about Rule 702’s familiar standards for admission of expert testimony. See Fed. R. Evid. 702. In Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the Supreme Court identified four factors to use when determining whether expert testimony is sufficiently reliable under Rule 702: “(1) whether [the

24-11011 Opinion of the Court 3

expert’s methodology] can be (and has been) tested; (2) whether it has been subjected to peer review and publication; (3) what its known or potential rate of error is, and whether standards controlling its operation exist; and (4) whether it is generally accepted in the field.” Brown, 415 F.3d at 1267; see Daubert, 509 U.S. at 593–94.

The district court here did not abuse its Daubert discretion.

Abimael Vasquez, the DEA forensic chemist, described at length how his lab uses gas chromatography-mass spectrometry (or “GC- MS”) to compare recovered substances with the DEA’s internal library of standard reference chemicals. Vasquez testified that GC- MS is a reliable test, that GC-MS is widely used and accepted in the scientific community, that the DEA built its reference-material library from an accredited source, and that the DEA double-checked reference material by running its own tests. On the basis of Vasquez’s extensive testimony, the district court found that he employed a reliable methodology in a reliable manner. The court assessed the Daubert factors and concluded that the government had made a strong enough showing because Vasquez “clearly testified that these methods are generally accepted in the scientific community ” and because “there is some peer review of especially the gas spectrometer, which is . . . considered the gold standard by at least some peer-reviewed literature.” Day Three Trial Tr. at 289:10–17, Dkt. No. 160. There’s no reason to think that Vasquez wasn’t a credible witness, and in any event, witness credibility is “the province of the factfinder.” United States v. Copeland, 20 F.3d 412, 413 (11th Cir. 1994). And most importantly, Rule 702’s inquiry is “a flexible one”; there is no “definitive checklist or test.” Daubert, 509

4 Opinion of the Court 24-11011

U.S. at 594, 593. On these facts, and in these circumstances, we cannot conclude that the district court abused its discretion in admitting Vasquez’s testimony.

Jackasal has one principal argument to the contrary. As he sees things, it is error for a district court to allow expert testimony to be presented to a jury when the only justification for the reliability of the expert’s method is that it is generally accepted. Jackasal concedes our previous holding that “[i]n the right circumstances,” a district court may admit “expert opinion evidence that does not meet three of the four Daubert factors.” Brown, 415 F.3d at 1267. But here—he insists—the district court relied on just one Daubert factor (general acceptance), and this case doesn’t have the “right circumstances.” He stresses in particular the fact that Vasquez testified to a jury, while the expert in Brown testified in a bench trial. See id. at 1269 (“There is less need for the gatekeeper to keep the gate when the gatekeeper is keeping the gate only for himself.”).

Jackasal’s rigid position is inconsistent the Daubert test’s flexible character. “Daubert’s list of specific factors neither necessarily nor exclusively applies to all experts or in every case.” Kumho Tire Co. v. Carmichael, 526 U.S. 137, 141 (1999). “Rather, the law grants a district court the same broad latitude when it decides how to determine reliability as it enjoys in respect to its ultimate reliability determination.” Id. at 142. Here, the district court was well within its discretion to conclude that at least one Daubert factor wasn’t quite suited to assessing the reliability of Vazquez’s method. The court reasoned that “given the kind of test at issue,” “falsi[fia]bility”

24-11011 Opinion of the Court 5

isn’t “something that makes sense for the test that we have.” Day Three Trial Tr. at 289:22–290:2. We defer to the district court’s judgment on this point.

More importantly, Jackasal gives the district court too little credit. It isn’t quite right to say—as Jackasal does—that the district court applied a “one-factor test.” Br. of Appellant at 23. Yes, the district court found that Vasquez’s methods “are generally accepted ” (the fourth Daubert factor). Day Three Trial Tr. at 289:11. But the district also found that GC-MS testing “is considered the gold standard by at least some peer-reviewed literature” (a reference to the second Daubert factor). Id. at 289:13–15. While Jackasal protests that the DEA’s specific application of GC-MS testing hasn’t been the subject of any peer-reviewed literature, Br. of Appellant at 11, he never provides any reason to believe that GC-MS more generally is anything other than the “gold standard.” We will not nit-pick the precise level of generality at which peer-reviewed literature may reasonably suggest to a district court that expert testimony is reliable. So, in light of the above, even considering that the evidence was presented to a jury, we don’t see how the district court could have “abdicat[ed] its gatekeeping role.” Brown, 415 F.3d at 1266.

II

We “will not overturn a jury’s verdict if there is any reasonable construction of the evidence that would have allowed the jury to find the defendant guilty beyond a reasonable doubt.” United States v. Clay, 832 F.3d 1259, 1294 (11th Cir. 2016) (citation

USCA11 Case: 24-11011 Document: 45-1 Date Filed: 09/02/2025 Page: 6 of 8

6 Opinion of the Court 24-11011

Free access — add to your briefcase to read the full text and ask questions with AI

United States v. Kavon Jackasal, (11th Cir. 2025).

United States v. Kavon Jackasal (United States v. Kavon Jackasal) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

Related

United States v. Ronald Keith Brown
415 F.3d 1257 (Eleventh Circuit, 2005)
Daubert v. Merrell Dow Pharmaceuticals, Inc.
509 U.S. 579 (Supreme Court, 1993)
Kumho Tire Co. v. Carmichael
526 U.S. 137 (Supreme Court, 1999)
United States v. Dwaine Copeland
20 F.3d 412 (Eleventh Circuit, 1994)
United States v. Jack Kelly Joseph
709 F.3d 1082 (Eleventh Circuit, 2013)
Burrage v. United States
134 S. Ct. 881 (Supreme Court, 2014)
United States v. Peter E. Clay
832 F.3d 1259 (Eleventh Circuit, 2016)
United States v. Vanston Venner Williams
865 F.3d 1328 (Eleventh Circuit, 2017)
United States v. Robert William Barton
909 F.3d 1323 (Eleventh Circuit, 2018)