UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT UNITED STATES OF AMERICA, No. 23-912 D.C. No. Plaintiff - Appellee, 9:22-cr-00052- DLC-1 v. DEREK STEVEN TRUMBULL, OPINION Defendant - Appellant.

Appeal from the United States District Court for the District of Montana Dana L. Christensen, District Judge, Presiding

Argued and Submitted May 6, 2024 Seattle, Washington

Filed August 22, 2024

Before: William A. Fletcher, Carlos T. Bea, and John B. Owens, Circuit Judges.

Opinion by Judge Owens; Concurrence by Judge Bea 2 USA V. TRUMBULL

SUMMARY *

Criminal Law

The panel affirmed a sentence imposed on Derek Steven Trumbull following his guilty plea to being a felon in possession of a firearm. Trumbull challenged the district court’s calculation of his Guidelines range—specifically, the increase of his offense level under U.S.S.G. § 2K2.1(a)(4)(B) on the ground that the offense involved a semiautomatic firearm that is capable of accepting a large capacity magazine. Section 2K2.1 does not define a “semiautomatic firearm that is capable of accepting a large capacity magazine,” but Application Note 2 of the commentary to § 2K2.1 says it means:

a semiautomatic firearm that has the ability to fire many rounds without reloading because at the time of the offense (A) the firearm had attached to it a magazine or similar device that could accept more than 15 rounds of ammunition; or (B) a magazine or similar device that could accept more than 15 rounds of ammunition was in close proximity to the firearm.

Trumbull did not dispute that the firearm he possessed, a Glock 17 loaded with a magazine containing seventeen * This summary constitutes no part of the opinion of the court. It has been prepared by court staff for the convenience of the reader. USA V. TRUMBULL 3

rounds of nine-millimeter ammunition, fell within Application Note 2. Instead, he attacked Application Note 2 on its face as an invalid interpretation of § 2K2.1 under Kisor v. Wilkie, 588 U.S. 558 (2019). The panel held that Application Note 2’s definition of “large capacity magazine” warrants deference under Kisor because (1) the term “large capacity magazine” is ambiguous within the meaning of Kisor because of the relative nature of the word large; (2) Application Note 2 is a reasonable interpretation of “large capacity magazine”; and (3) Application Note 2 meets the three “especially important markers for identifying” when deference is appropriate in that (a) Application Note 2 is the Sentencing Commission’s official position, (b) the interpretation implicates the agency’s substantive expertise, and (c) Application Note 2 was an exercise of the Commission’s fair and considered judgment. The panel therefore concluded that the district court did not err in applying § 2K2.1(a)(4)(B), as interpreted by Application Note 2, to Trumbull’s base offense level. Concurring in the judgment, Judge Bea disagreed with the majority that Application Note 2 of the commentary to § 2K2.1 is entitled to deference under Kisor because, in his view, the term “large capacity magazine” is not “genuinely ambiguous.” Applying the traditional tools of construction to interpret the term “large capacity magazine,” and applying that term to the facts of this case, he concluded that the Glock 17 that Trumbull possessed at the time of the offense— which could accept a magazine with 17 rounds of ammunition—unambiguously qualifies as a “semiautom